The Cover,protective,tunnel Airlock, cataloged under National Stock Number 4240-01-331-3256, is classified within Federal Supply Class 4240 (Safety and Rescue Equipment) of the Fire Fighting, Rescue, and Safety Equipment group. Government technical data includes 1 specification, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4240-01-331-3256 |
| Item Name | Cover,protective,tunnel Airlock |
| FSC / FSG | 4240 / 42 — Safety and Rescue Equipment |
| Status | ACTIVE |
| General Characteristics Item Description | BONDING OF SEAMS TO BE ACCOMPLISHED BY USING THERMAL HEAT SEAL |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL D — Destroy Item |
| Hazard | Possible hazard — SDS may be required (DLA HMIC P) |
| Criticality Code | N |
| Reference | Meaning |
|---|---|
| 5-19-11233 | 3/2 Design control — primary reference U.S. Government activity |
NSN 4240-01-331-3256 is a Cover,protective,tunnel Airlock, classified under FSC 4240, Safety and Rescue Equipment. Status: active.
Key specifications for 4240-01-331-3256: General Characteristics Item Description: BONDING OF SEAMS TO BE ACCOMPLISHED BY USING THERMAL HEAT SEAL; End Item Identification: XM28,SIMPLIFIED COLLECTIVE PROTECTION EQUIPMENT SYSTEM. 1 specification is 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.
NSN 4240-01-331-3256 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.