The Whisker,helmet, cataloged under National Stock Number 4220-01-331-1973, is classified within Federal Supply Class 4220 (Marine Lifesaving and Diving Equipment) of the Fire Fighting, Rescue, and Safety Equipment group. The manufacturer of record is Kirby Morgan Dive Systems Inc. The record lists 2 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4220-01-331-1973 |
| Primary Part Number | 510-555 |
| Item Name | Whisker,helmet |
| FSC / FSG | 4220 / 42 — Marine Lifesaving and Diving Equipment |
| Manufacturer | Kirby Morgan Dive Systems Inc |
| Status | ACTIVE |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| 510-555 PRIMARY | Kirby Morgan Dive Systems Inc (USA) |
| 592-6318285 | Naval Sea Systems Command (USA) |
NSN 4220-01-331-1973 is a Whisker,helmet, manufactured by Kirby Morgan Dive Systems Inc, classified under FSC 4220, Marine Lifesaving and Diving Equipment. Status: active.
NSN 4220-01-331-1973 has 2 manufacturer part numbers on file: 510-555 (Kirby Morgan Dive Systems Inc), 592-6318285 (Naval Sea Systems Command).
Key specifications for 510-555: End Item Identification: MK21 MOD1 DIVING HELMET. 0 specifications are documented in the U.S. Government catalog.
No hazard code in the DLA record (HMIC N). 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.