The Neckstrap Assembly,respirator, cataloged under National Stock Number 4240-01-251-3278, is classified within Federal Supply Class 4240 (Safety and Rescue Equipment) of the Fire Fighting, Rescue, and Safety Equipment group. Government technical data includes 2 specifications, cited from the U.S. Government catalog. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 3 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4240-01-251-3278 |
| Item Name | Neckstrap Assembly,respirator |
| FSC / FSG | 4240 / 42 — Safety and Rescue Equipment |
| Status | ACTIVE |
| General Characteristics Item Description | INCLUDES BUCKLE,LOOP RING AND NECKSTRAP; SOLE SOURCE REQUIRED BY STATUTE 6.302 |
| Criticality Code Justification | TEXT |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | Possible hazard — SDS may be required (DLA HMIC P) |
| Criticality Code | Y |
| Reference | Meaning |
|---|---|
| 51552 | 5/9 Secondary reference American Optical Co |
| 51552 | 3/9 Design control — primary reference Aearo Company 1 Dba Aearo Div Ao Safety Occupational Prescription Eyewear |
| 51552 | 5/9 Secondary reference U.S. Government activity |
| 51552 | 5/9 Secondary reference 3m Company |
NSN 4240-01-251-3278 is a Neckstrap Assembly,respirator, classified under FSC 4240, Safety and Rescue Equipment. Status: active.
3 possible matches (shared part number, not a government interchangeability claim): 6530-01-281-5320, 2940-01-625-2276, 4720-01-644-0311. Verify interchangeability with system specifications before substitution.
Key specifications for 4240-01-251-3278: General Characteristics Item Description: INCLUDES BUCKLE,LOOP RING AND NECKSTRAP; SOLE SOURCE REQUIRED BY STATUTE 6.302; Criticality Code Justification: TEXT; End Item Identification: AMERICAM OPTICAL MODEL 7 STAR SERIES 7700 AND 7800 RESPIRATOR. 2 specifications are documented in the U.S. Government catalog.
Possible hazard — SDS may be required (DLA HMIC P). Hazard information on this page is shown exactly as it appears in the DLA record.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-16.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.