# EDGAR Filing Document

**Accession Number:** 0001506492
**File Stem:** 0001140361-26-011775
**Filing Date:** 2026-3
**Character Count:** 26180
**Document Hash:** 8100dd9d26718db6bf691a9aa9be86a3
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001140361-26-011775.hdr.sgml**: 20260327

**ACCESSION NUMBER**: 0001140361-26-011775

**CONFORMED SUBMISSION TYPE**: 8-K

**PUBLIC DOCUMENT COUNT**: 13

**CONFORMED PERIOD OF REPORT**: 20260326

**ITEM INFORMATION**: Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers: Compensatory Arrangements of Certain Officers

**ITEM INFORMATION**: Financial Statements and Exhibits

**FILED AS OF DATE**: 20260327

**DATE AS OF CHANGE**: 20260327

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Nuwellis, Inc.
- **CENTRAL INDEX KEY:** 0001506492
- **STANDARD INDUSTRIAL CLASSIFICATION:** ELECTROMEDICAL & ELECTROTHERAPEUTIC APPARATUS [3845]
- **ORGANIZATION NAME:** 08 Industrial Applications and Services
- **EIN:** 680533453
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 8-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-35312
- **FILM NUMBER:** 26808248

**BUSINESS ADDRESS:**
- **STREET 1:** 12988 VALLEY VIEW ROAD
- **CITY:** EDEN PRAIRIE
- **STATE:** MN
- **ZIP:** 55344
- **BUSINESS PHONE:** 952-345-4200

**MAIL ADDRESS:**
- **STREET 1:** 12988 VALLEY VIEW ROAD
- **CITY:** EDEN PRAIRIE
- **STATE:** MN
- **ZIP:** 55344

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** CHF Solutions, Inc.
- **DATE OF NAME CHANGE:** 20170523

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Sunshine Heart, Inc.
- **DATE OF NAME CHANGE:** 20101124

?xml version='1.0' encoding='ASCII'?

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### UNITED STATES

### SECURITIES AND EXCHANGE COMMISSION

#### Washington, D.C. 20549

### FORM 8-K

#### Current Report Pursuant to Section 13 or 15(d) of

#### the Securities Exchange Act of 1934
Date of Report (Date of earliest event reported): **March 26, 2026**

## Nuwellis, Inc.

#### (Exact Name of Registrant as Specified in its Charter)

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| | | |
|:---|:---|:---|
| **Delaware**<br>| **001-35312**<br>| **No. 68-0533453** |
| **(State or Other Jurisdiction of Incorporation or Organization)** | **(Commission File Number)** | **(I.R.S. Employer Identification No.)** |

---

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| | |
|:---|:---|
| **12988 Valley View Road, Eden Prairie, MN**<br> **(Address of Principal Executive Offices)** | **55344**<br>**(Zip Code)** |

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(952) 345-4200

#### (Registrant's Telephone Number, Including Area Code)

#### Not Applicable

#### (Former Name or Former Address, if Changed Since Last Report)
Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

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| | | |
|:---|:---|:---|
| Title of each class | Trading Symbol(s) | Name of each exchange on which<br> registered |
| Common Stock, par value $0.0001 per share<br>| NUWE<br>| Nasdaq Capital Market<br>|

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Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

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|:---|:---|
| **Item 5.02** | **Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.** |

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On March 26, 2026, each of Mika Grasso and Katharyn Field resigned, effective immediately, from the Board of Directors (the "***Board***") of Nuwellis, Inc. (the "***Company***").

Mr. Grasso resigned due to the matters set forth in his resignation letter, which details various disagreements with the Company, including the Company's and its advisors' alleged failure to timely provide him with certain information, such that he believes that he is no longer able to effectively fulfill his duties as a director. A copy of Mr. Grasso's resignation letter delivered to the Board of Directors of the Company is filed herewith as Exhibit 17.1.

Ms. Field resigned due to the matters set forth in her resignation letter, which details various disagreements with the Company, including the Company's and its advisors' alleged failure to timely provide her with certain information, such that she believes that she is no longer able to effectively fulfill her duties as a director. A copy of Ms. Field's resignation letter delivered to the Board of Directors of the Company is filed herewith as Exhibit 17.2.

The Company and the continuing members of the Board disagree with the allegations made by Mr. Grasso and Ms. Field in their respective resignation letters and take exception to their characterizations of facts and their claimed conclusions. In their resignation letters both Mr. Grasso and Ms. Field make certain allegations against the Company's management, other Board members and the Company's advisors, which the Company believes contain numerous errors of fact, misleading speculations and malicious interpretations of certain factual events.

The Company is providing a copy of the disclosures contained in this Current Report on Form 8-K to each of Mr. Grasso and Ms. Field on the date which this Current Report on Form 8-K is being filed with the Securities and Exchange Commission. The Company is also providing each of Mr. Grasso and Ms. Field with the opportunity to furnish the Company with a letter stating whether he or she agrees with the statements made by the Company in this Current Report on Form 8-K and, if not, the respects in which they do not agree. The Company will file any such letter received from Mr. Grasso and/or Ms. Field with the Securities and Exchange Commission as an exhibit by amendment to this Current Report on Form 8-K within two business days after receipt by the Company, if at all.

As a result of these resignations, on March 27, 2026, the Board determined to decrease the size of the Board from seven (7) to five (5) members, effective immediately.

#### CAUTIONARY NOTE
IN THE INTERESTS OF FULL AND COMPLETE DISCLOSURE, THE RESIGNATION LETTERS DELIVERED BY MR. GRASSO AND MS. FIELD ARE BEING FILED IN EXACTLY THE FORM IN WHICH THEY WERE PROVIDED TO THE COMPANY, WITHOUT REDACTION OR MODIFICATION OF ANY KIND. THE COMPANY WISHES TO EMPHASIZE THAT THE RESIGNATION LETTERS REFLECT ONLY THE THOUGHTS AND BELIEFS OF MR. GRASSO AND MS. FIELD, WHICH MAY OR MAY NOT CORRESPOND WITH THE THOUGHTS AND BELIEFS OF ANY REPRESENTATIVE OF THE COMPANY, AND MANY OF WHICH ARE EXPRESSLY CONTRARY TO THE THOUGHTS AND BELIEFS OF THE COMPANY'S MANAGEMENT AND THE BOARD AND TO THE FACTS RELEVANT TO THE VARIOUS ISSUES. AS A RESULT, THE COMPANY TAKES NO RESPONSIBILITY FOR THE CONTENTS OF THE RESIGNATION LETTERS, INCLUDING ANY RESPONSIBILITY THAT MAY ARISE IN CONNECTION WITH ANY OF THE FORWARD-LOOKING STATEMENTS CONTAINED IN THE RESIGNATION LETTERS. STOCKHOLDERS AND INVESTORS ARE STRONGLY ENCOURAGED TO RELY ONLY ON THE INFORMATION ABOUT THE COMPANY CONTAINED IN THE COMPANY'S FILINGS WITH THE SECURITIES AND EXCHANGE COMMISSION, INCLUDING THE COMPANY'S MOST RECENT ANNUAL REPORT ON FORM 10-K, QUARTERLY REPORTS ON FORM 10-Q AND CURRENT REPORTS ON FORM 8-K.

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| | |
|:---|:---|
| **Item 9.01** | **Financial Statements and Exhibits.** |

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(d) Exhibits:

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| | |
|:---|:---|
| **Exhibit No.** | **Description** |
| [17.1](ef20069181_ex17-1.htm) | Letter, dated March 26, 2026, to the Board of Directors of Nuwellis, Inc. from Mika Grasso |
| [17.2](ef20069181_ex17-2.htm) | Letter, dated March 26, 2026, to the Board of Directors of Nuwellis, Inc. from Katharyn Field<br>|
| 104 | Cover Page Interactive Data File (Embedded within the Inline XBRL Document). |

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#### SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

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| | | |
|:---|:---|:---|
| Date: March 27, 2026 | **NUWELLIS, INC.** | **NUWELLIS, INC.** |
|  | By: | /s/ John L. Erb |

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Name: John L. Erb <br> Title: President and Chief Executive Officer

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## Exhibit 17.1

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**Exhibit 17.1**<br>

March 26, 2026

Board of Directors

Nuwellis, Inc.

c/o John Erb, Chief Executive Officer

and Chairman of the Board

Re: Resignation from Board of Directors

<br> Dear Members of the Board:

I, Mika Grasso, hereby resign from the Board of Directors of Nuwellis, Inc., effective immediately for the reasons noted below.

I accepted this role with the expectation that I would be able to discharge my fiduciary duties through a thoughtful, informed, and constructive process, and that management and the Board would support appropriate diligence and meaningful engagement on significant corporate matters. Instead, throughout my tenure, I encountered repeated obstacles to informed Board participation, persistent failures to provide information and meeting materials in a timely manner, and a pattern of conduct that undermined my ability to serve effectively as an independent director.

From the beginning of my service, I made every effort to engage seriously and constructively with management and the Board. On January 23, 2026, I sent an introductory email to the Board and requested a meeting to discuss the upcoming transaction and acquisition. Before that, I had completed and submitted various onboarding materials on January 14 and January 15, 2026, executed my Director Invitation Letter and Indemnity Agreement on January 21, 2026, and provided my biography for the Company's press release and Form 8-K disclosure on January 22, 2026. I also notarized and submitted my Form ID and Power of Attorney on January 23, 2026, and signed the S-1 on January 26, 2026, the same day I was requested to do so. I also made an entreaty for the Board to consider and discuss impending Nasdaq compliance issues affecting listing rules, but that was met with deafening silence and no action. These steps reflected my good-faith effort to support the Company and perform my responsibilities diligently from the outset.

At the same time, however, the Company did not provide the corresponding transparency and engagement necessary for independent directors to fulfill their oversight role. When I joined the Board, I was promised a comprehensive discussion with Mr. Erb regarding the proposed acquisition so that I could properly diligence and understand the transaction. That discussion never meaningfully occurred. Prior to joining the Board, I learned that an Executive Committee was created immediately before I joined, but was never informed about it. This Executive Committee, however, approved a highly dilutive transaction which I learned about from the filing of an 8-K. Nevertheless, I was asked to sign the resale S-1 within a matter of hours. And, a meeting to review the acquisition that was scheduled for January 28, 2026, was rescheduled at Mr. Erb's request, and then canceled altogether on January 29, 2026. More broadly, meetings regarding the acquisition were scheduled and then canceled multiple times, and the acquisition proceeded without any meaningful discussion. That sequence is emblematic of the broader governance problems that led to my resignation.

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I also raised concerns when serious issues came to my attention, but those concerns were not met with meaningful engagement. On January 30, 2026, I received notice of threatened litigation alleging contract breach and fiduciary duty claims, and on January 30, 2026, I emailed the Board expressing concern regarding that litigation notice and the lack of response to prior inquiries. On February 3, 2026, a shareholder reached out threatening litigation for the destruction of shareholder value. Rather than being treated as matters warranting careful Board-level attention and open discussion, these concerns were met with the same pattern of inadequate response and exclusion.

The Company's handling of Board meetings and Board process likewise made meaningful participation increasingly difficult. Meetings were frequently canceled on short notice, were at times scheduled despite known conflicts that had been communicated in advance, and agendas and supporting materials were not consistently provided in advance of Board meetings and in certain instances were not provided at all. On February 24, 2026, I was voted off all committees during a short Board meeting for which no agenda had been provided in advance. A Board process in which independent directors are excluded from key discussions, deprived of advance materials, and then removed from committees without a proper agenda is not a process that fosters responsible governance.

The same pattern continued with the Company's public reporting. I received a draft of the Annual Report Form 10-K on March 4, 2026, and comments were provided on March 9, 2026, but our comments were barely addressed and brushed off without sufficient engagement. Multiple substantive comments and questions I raised regarding the Form 10-K were largely disregarded or addressed without sufficient detail or engagement. A Board cannot responsibly oversee disclosure obligations where substantive director comments are not meaningfully considered.

More broadly, my experience on the Board was marked by a degree of hostility and unprofessionalism from management and certain members of the Board that made constructive service increasingly untenable. That experience included repeated failures to provide requested information, repeated disruption of meetings, disregard of director comments, and exclusion from committee participation and key discussions. I joined the Board to contribute constructively toward enhancing stockholder value and to help the Company address important issues. Instead, I found that efforts to dig into problems, understand material matters, and improve governance were not meaningfully supported.

For all of these reasons, I can no longer continue serving as a director. My resignation is based on serious concerns regarding the Company's governance, its treatment of independent directors, and the repeated impediments placed in the way of informed and constructive Board oversight. Throughout my tenure, I made every effort to fulfill my obligations conscientiously and in good faith, but I no longer have confidence that I can do so effectively under the circumstances.

Please provide this letter to the full Board and maintain it with the Company's corporate records. Please also take all steps necessary to promptly disclose my resignation and the reasons in the Company's filings and public records.

Sincerely,<br>Mika Grasso

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## Exhibit 17.2

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#### Exhibit 17.2<br>

March 26, 2026

<br> Board of Directors

Nuwellis, Inc.

c/o Neil Ayotte General Counsel and Secretary & John Erb, Chief Executive Officer and Chairman of the Board

**Re: Resignation from Board of Directors — Effective Immediately**<br>

Dear Members of the Board:

I, Katharyn Field, hereby resign from the Board of Directors of Nuwellis, Inc., effective immediately. I do not take this step lightly. I accepted this role expecting to discharge my fiduciary duties through a constructive process. Instead I encountered a sustained pattern of obstruction, exclusion, hostility, and reprisal that made it impossible to serve as an independent director in anything other than name.

What follows is a factual record of the Company's conduct. I set it out in full because the investing public, the auditors, and the regulators are entitled to understand exactly why an independent director concluded that continued service would lend a false appearance of governance to a Board that does not practice it.

Circumvention of Banking Relationship and Transactions Lacking Oversight

I learned weeks after the fact that an Executive Committee was created on January 21, 2026—the very same day I was appointed to the Board. That committee of three members held a special meeting on January 29, 2026, and approved the Ladenburg private placement, among other items, in a transaction I was never consulted on and never approved. A brief call with another board member yielded nothing beyond a vague reference to a "duly convened subcommittee."

Following the private placement which I learned about only via newswire, I pressed Mr. Ayotte for a week: What committee? What minutes? After all, I had joined the Board and repeatedly requested meetings, yet had not been invited to a single one. Allegedly this executive committee had been formed the same day as my appointment and met without notice to me or Mike Grasso to approve a highly dilutive financing, the "PIPE" transaction. The timing is not coincidental. Two independent directors were seated and, on the same day, a committee was created to ensure neither director would vote on material transactions before the Company.

I also note that this transaction was completed in direct circumvention of the Company's exclusive engagement with EF Hutton—a breach that subsequently incited litigation against the Company. At no time did the entire Board discuss EF Hutton exclusivity or seek a waiver. I

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reiterate: I had no knowledge of this transaction prior to its public filing, I did not approve it, and was deprived of any opportunity to question or vote on it.

Rendiatech Acquisition Review

I was appointed to the Nuwellis Board on January 21, 2026. I completed every onboarding step immediately: Director Invitation Letter and Indemnity Agreement (January 21), biography for the 8-K (January 22), Form ID and Power of Attorney (January 23), and S-1 signature the same day it was requested (January 26). I sent an introductory email to the Board on January 22 and requested a substantive meeting to discuss the pending Rendiatech acquisition.

That meeting never occurred. On January 27, Mr. Erb finally provided some information on Rendiatech—only to reveal that the deal had grown in size substantially since it was first announced. A meeting to review the acquisition was scheduled for January 28, rescheduled at Mr. Erb's request, and then canceled outright on January 29 with no notice or explanation. The acquisition proceeded without any meaningful independent director involvement.

CFO Appointment Without Board Deliberation

On January 29 Mr. Erb emailed the Board to announce a new CFO had been hired and requested written consent. I asked multiple questions about the hiring process and whether the Board had considered more cost-effective alternatives. I was shut down. On the same day, the PIPE transaction, CFO appointment, and acquisition were announced publicly—all without meaningful Board input. These were not administrative matters; they were among the most consequential decisions a Board can and should make, and independent directors were excluded.

Denial of Information

Throughout my tenure, requests for basic information were met with delay, obstruction, or silence:

● On February 4, I was surprised Mr. Ayotte reached out requesting a power of attorney to be completed after being led to believe Hongiman handled the Form 3 filing as part of onboarding.

● I tried in the following week to complete my Form 3 filing multiple times but the form would not process. On February 11, it came to light that my EDGAR credentials (specifically the CCC code) had been changed. Sullivan & Worcester spent hours with me rectifying in order to submit Form 3.

● On February 5, Mr. Ayotte begrudgingly provided only minimal documents I requested for company diligence while stating this was "not the most efficient use of his time."

● D&O insurance documents were requested repeatedly; Mr. Ayotte finally provided them on February 16.

● On February 11, I emailed Mr. Ayotte requesting an introduction to the auditors, information on submitting invoices, and a 1099. No response.

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● On March 11 it was further discovered that Mr. Ayotte and Mr. Adam Garvey are the only and remain the only administrators of my Edgar Next account, hindering other companies' filings.

These were not isolated administrative lapses. They were calculated to prevent an independent director from performing the most basic functions of the role.

Ignored Litigation Risk and Governance Lapses

On January 30, the Board was notified of threatened litigation by EF Hutton alleging contract breaches stemming from the Ladenburg private placement. I sent a note to the Board summarizing my concerns including the unauthorized financing, breach of exclusivity, governance failures, that D&O carrier must be placed on notice, and requesting Company records. No one responded except Mika Grasso. On January 31, I notified Honigman of potential malpractice since the PIPE transaction led to threatened litigation. No response. On February 3, Mr. Ayotte forwarded shareholder correspondence which also threatened litigation due to the PIPE transaction. On the same day, Mr. Ayotte blind-copied me on a company-wide email regarding preservation of records in anticipation of litigation—an extraordinary step that underscored the gravity of the situation, yet the Board took no collective action.

I called two Special Board Meetings on February 4 and 5 to address these corporate governance failures and material matters. Only Mika Grasso, counsel to the independent directors, and I attended. The remaining directors refused to participate in oversight of their own Company.

Defamation by the Chairman and CEO

During a call with principals and counsel on February 9, Mr. Erb falsely accused me of having a "relationship" with a potential investor—a baseless, slanderous statement made in the presence of counsel that was plainly intended to discredit me and deflect attention from the governance failures I had raised.

Removal from Committees and Exclusion from Meetings

On February 24, the first and one of the only Board meetings I was invited to and for which no agenda or prereads had been provided in advance, Mika Grasso and I were voted off all committees and replaced by two additional directors. The Board was reconstituted to exclude the independent voices that had been asking inconvenient questions. This was not governance; it was retaliation.

The pattern continued with the scheduling of the March 27 Board meeting. On March 18, I communicated that I had preexisting medical appointments all morning and could attend in the afternoon. On March 24, I received notice the meeting was set for 10:00 a.m.—a time chosen to prevent my attendance.

Auditor Discussion and Financial Reporting

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In February I tried to report my concerns to the Company's auditor. On March 2 the auditors responded. During the March 3 call with Baker Tilly, Mika Grasso and I expressed concerns regarding the Company's governance, controls, and fiduciary responsibilities. The auditor further responded on March 4 that, "corporate governance is relevant to our audit because it represents a component of the control environment and entity-level controls" and that our concerns had been evaluated in the context of their audit procedures, risk assessment, and communications with the audit committee. This was a validation of the seriousness of the issues raised.

On March 10, I received an updated draft 10-K. The initial draft provided a week prior had included a remark that my own appointment may be at odds with NASDAQ listing rules. Mr. Ayotte disclaimed any knowledge and stated, "I think it may have been an overzealous outside lawyer." Subsequent extensive comments on the updated version were brushed off with little engagement. On March 10, Mr. Ayotte and Mr. Erb urged me to sign a written consent approving the financial statements. I refused, citing my continued concerns with the Company's financial statements and consistent poor performance across every reasonable metric of value. A Board cannot responsibly oversee its disclosure obligations when substantive independent director comments are not meaningfully considered.

Reprisal/ Retaliation

On March 26 Mr. Erb emailed to inform me that I will not be renominated to the Board. The message was unmistakable: the price for attempting to fulfill one's fiduciary duties at Nuwellis is removal.

I joined this Board to contribute constructively toward enhancing stockholder value and to help the Company navigate serious issues. I was met instead with a governance apparatus designed to insulate management from accountability: information withheld, meetings canceled, committees stripped, concerns ignored, character attacked, and ultimately, a seat revoked.

I do not lend my name and professional reputation to a Board that operates in this manner. My resignation is based on serious and well-documented concerns regarding the Company's governance, its treatment of independent directors, and the integrity of its filings. Throughout my tenure, I made every effort to fulfill my obligations conscientiously and in good faith but was prevented at every step from doing so.

Please provide this letter to the full Board and maintain it with the Company's corporate records. Take all steps necessary to promptly disclose my resignation and the reasons in the Company's filings and public records, including but not limited to on Form 8-K, as required by applicable SEC rules and regulations. I expect strict compliance with Item 5.02 of Form 8-K and all related disclosure obligations.

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|:---|
| Sincerely, |
| /s/Katharyn Field |
| Katharyn Field |

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