The Filter Set,gas-Particulate, cataloged under National Stock Number 4240-01-666-7509, 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 Hdt Expeditionary Systems Inc. The record lists 3 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Item Name | Filter Set,gas-Particulate |
| FSC / FSG | 4240 — Safety and Rescue Equipment (FSG 42) |
| Manufacturers | Hdt Expeditionary Systems Inc (CAGE 0WJE1); Lockheed Martin Corporation Div Rms (CAGE 03538) |
| Parameter | Value |
|---|---|
| NSN | 4240-01-666-7509 |
| Primary Part Number | 77A581079-031 |
| Item Name | Filter Set,gas-Particulate |
| FSC / FSG | 4240 / 42 — Safety and Rescue Equipment |
| Manufacturer | Hdt Expeditionary Systems Inc |
| Status | ACTIVE |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL D — Destroy Item |
| Hazard | Possible hazard — SDS may be required (DLA HMIC P) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| 77A581079-031 PRIMARY | Hdt Expeditionary Systems Inc (USA) |
| 77A581079 PRIMARY | Hdt Expeditionary Systems Inc (USA) |
| 77A581079P1 | Lockheed Martin Corporation Div Rms (USA) |
NSN 4240-01-666-7509 is a Filter Set,gas-Particulate, manufactured by Hdt Expeditionary Systems Inc, classified under FSC 4240, Safety and Rescue Equipment. Status: active.
NSN 4240-01-666-7509 has 3 manufacturer part numbers on file: 77A581079-031 (Hdt Expeditionary Systems Inc), 77A581079 (Hdt Expeditionary Systems Inc), 77A581079P1 (Lockheed Martin Corporation Div Rms).
1 possible match (shared part number, not a government interchangeability claim): 4140-01-720-9284. Verify interchangeability with system specifications before substitution.
Possible hazard — SDS may be required (DLA HMIC P). Hazard information on this page is shown exactly as it appears in the DLA record.
NSN 4240-01-666-7509 has DEMIL Code D. Demilitarization may be required before disposal or transfer to non-military entities.
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.