The Hearing Protector, cataloged under National Stock Number 4240-01-024-9501, 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 American Optical Co. Government technical data includes 1 specification, 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. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4240-01-024-9501 |
| Primary Part Number | 1720 |
| Item Name | Hearing Protector |
| FSC / FSG | 4240 / 42 — Safety and Rescue Equipment |
| Manufacturer | American Optical Co |
| Status | ACTIVE |
| General Characteristics Item Description | EAR GUARDING NOISE SUPPRESSION,EAR-PHONE HEAD RETAINER STYLE,EASY ADJUSTMENT,LIGHT WEIGHT,FITS ALL HEADS |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | Possible hazard — SDS may be required (DLA HMIC P) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| 1720 PRIMARY | American Optical Co (USA) |
NSN 4240-01-024-9501 is a Hearing Protector, manufactured by American Optical Co, classified under FSC 4240, Safety and Rescue Equipment. Status: active.
NSN 4240-01-024-9501 has 1 manufacturer part number on file: 1720 (American Optical Co).
Key specifications for 1720: General Characteristics Item Description: EAR GUARDING NOISE SUPPRESSION,EAR-PHONE HEAD RETAINER STYLE,EASY ADJUSTMENT,LIGHT WEIGHT,FITS ALL HEADS. 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.
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.