# EDGAR Filing Document

**Accession Number:** 0001434524
**File Stem:** 0001104659-25-070368
**Filing Date:** 2025-7
**Character Count:** 2726
**Document Hash:** 2e3c6042ecc1b571f184f50a724c052f
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-25-070368.hdr.sgml**: 20250825

**ACCESSION NUMBER**: 0001104659-25-070368

**CONFORMED SUBMISSION TYPE**: CORRESP

**PUBLIC DOCUMENT COUNT**: 2

**FILED AS OF DATE**: 20250724

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** ClearSign Technologies Corp
- **CENTRAL INDEX KEY:** 0001434524
- **STANDARD INDUSTRIAL CLASSIFICATION:** INDUSTRIAL INSTRUMENTS FOR MEASUREMENT, DISPLAY, AND CONTROL [3823]
- **ORGANIZATION NAME:** 08 Industrial Applications and Services
- **EIN:** 000000000
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** CORRESP

**BUSINESS ADDRESS:**
- **STREET 1:** 8023 E. 63RD PLACE, SUITE 101
- **CITY:** TULSA
- **STATE:** OK
- **ZIP:** 74133
- **BUSINESS PHONE:** (918) 236-6461

**MAIL ADDRESS:**
- **STREET 1:** 8023 E. 63RD PLACE, SUITE 101
- **CITY:** TULSA
- **STATE:** OK
- **ZIP:** 74133

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** CLEARSIGN COMBUSTION CORP
- **DATE OF NAME CHANGE:** 20080507

![](tm2521654d1_correspimg01.jpg)

July 24, 2025

<u>VIA EDGAR</u>

U.S. Securities and Exchange Commission<br> Division of Corporation Finance<br> 100 F Street, N.E.<br> Washington, D.C. 20549

---

| | |
|:---|:---|
| **RE:** | **ClearSign Technologies Corporation** |
|  | **Registration Statement on Form S-3** |
|  | **Filed July 17, 2025** |
|  | **File No. 333-288736** |
|  | **Acceleration Request** |
|  | **Requested Date: Monday, July 28, 2025** |
|  | **Requested Time: 4:30 p.m. Eastern Time** |

---

Ladies and Gentlemen:

In accordance with Rule 461 under the Securities Act of 1933, as amended, the undersigned registrant (the "<u>Registrant</u>") hereby requests that the Securities and Exchange Commission (the "<u>Commission</u>") take appropriate action to cause the above-referenced Registration Statement on Form S-3 (File No. 333-288736) (the "<u>Registration Statement</u>") to become effective on Monday, July 28, 2025, at 4:30 p.m. Eastern Time, or as soon thereafter as possible, or at such later time as the Registrant or its outside counsel, Mitchell Silberberg & Knupp LLP, may orally request via telephone call to the staff.

Once the Registration Statement has been declared effective, please orally confirm that event with our outside counsel by calling Blake Baron at (917) 546-7709.

---

| |
|:---|
| Very truly yours, |
| ClearSign Technologies Corporation |
| By: /s/ Colin James Deller |
| Colin James Deller |
| Chief Executive Officer |

---

cc: Gabriel Miranda, Esq., Mitchell Silberberg & Knupp LLP

ClearSign Technologies Corporation – 8023 East 63<sup>rd</sup> Place, Suite 101, Tulsa, Oklahoma 74133 – Tel: 206.673.4848 – <u>www.clearsign.com</u>