The Coupler,respirator, cataloged under National Stock Number 4240-01-250-9046, is classified within Federal Supply Class 4240 (Safety and Rescue Equipment) of the Fire Fighting, Rescue, and Safety Equipment group. The manufacturer of record is Square D Co Monroe Plant. Government technical data includes 2 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government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 | 4240-01-250-9046 |
| Primary Part Number | 51516 |
| Item Name | Coupler,respirator |
| FSC / FSG | 4240 / 42 — Safety and Rescue Equipment |
| Manufacturer | Square D Co Monroe Plant |
| Status | ACTIVE |
| General Characteristics Item Description | 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 |
| Part Number | Manufacturer |
|---|---|
| 51516 PRIMARY | Square D Co Monroe Plant (USA) |
| Reference | Meaning |
|---|---|
| 51516 | 3/9 Design control — primary reference U.S. Government activity |
NSN 4240-01-250-9046 is a Coupler,respirator, manufactured by Square D Co Monroe Plant, classified under FSC 4240, Safety and Rescue Equipment. Status: active.
NSN 4240-01-250-9046 has 1 manufacturer part number on file: 51516 (Square D Co Monroe Plant).
2 possible matches (shared part number, not a government interchangeability claim): 5315-01-309-6167, 6625-01-583-2422. Verify interchangeability with system specifications before substitution.
Key specifications for 51516: General Characteristics Item Description: SOLE SOURCE REQUIRED BY STATUTE 6.302; Criticality Code Justification: TEXT; End Item Identification: AMERICAN OPTICAL MODEL R5099 AND 7800 COMMANDER SERIES 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.