# EDGAR Filing Document

**Accession Number:** 0001434524
**File Stem:** 0000000000-25-007802
**Filing Date:** 2025-7
**Character Count:** 2429
**Document Hash:** 93bd7cedbcbb6f59193271cc6fac205b
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000000000-25-007802.hdr.sgml**: 20250825

**ACCESSION NUMBER**: 0000000000-25-007802

**CONFORMED SUBMISSION TYPE**: UPLOAD

**PUBLIC DOCUMENT COUNT**: 2

**FILED AS OF DATE**: 20250724

**FILED FOR**: 

**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:** UPLOAD
- **SEC FILE NUMBER:** 333-288736

**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
**PUBLIC REFERENCE ACCESSION NUMBER**: 0001104659-25-068740

## Text-Extract

```

                                                           July 24, 2025

Colin Deller
Chief Executive Officer
ClearSign Technologies Corporation
8023 East 63rd Place, Suite 101
Tulsa, OK 74133

        Re: ClearSign Technologies Corporation
            Registration Statement on Form S-3
            Filed July 17, 2025
            File No. 333-288736
Dear Colin Deller:

       This is to advise you that we have not reviewed and will not review your
registration
statement.

        Please refer to Rules 460 and 461 regarding requests for acceleration.
We remind you
that the company and its management are responsible for the accuracy and
adequacy of their
disclosures, notwithstanding any review, comments, action or absence of action
by the staff.

       Please contact Nicholas O'Leary at 202-551-4451 with any questions.

                                                           Sincerely,

                                                           Division of
Corporation Finance
                                                           Office of Industrial
Applications and
                                                           Services
cc:   Blake Baron, Esq.

```

### Attached PDF Documents

**Attachment 1:** `filename1`

_No text found in this document._