The Window,optical Instrument, cataloged under National Stock Number 1240-01-651-1682, is classified within Federal Supply Class 1240 (Optical Sighting and Ranging Equipment) of the Fire Control Equipment group. Government technical data includes 5 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 1240-01-651-1682 |
| Item Name | Window,optical Instrument |
| FSC / FSG | 1240 / 12 — Optical Sighting and Ranging Equipment |
| Status | ACTIVE |
| Surface Finish | POLISHED |
| Diameter | 0.57 INCHES NOMINAL IN |
| Bevel Angle in Deg | 0.45 NOMINAL |
| Material | GLASS OPTICAL LOCATION NOT OTHERWISE SPECIFIED |
| Thickness | 0.10 INCHES NOMINAL IN |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL Q — CCL Item — Commerce Control List |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Reference | Meaning |
|---|---|
| 6631581-1 | 3/2 Design control — primary reference U.S. Government activity |
NSN 1240-01-651-1682 is a Window,optical Instrument, classified under FSC 1240, Optical Sighting and Ranging Equipment. Status: active.
Key specifications for 1240-01-651-1682: Surface Finish: POLISHED; Diameter: 0.57 INCHES NOMINAL IN; Special Features: GRADE-A; Part Name Assigned by Controlling Agency: WINDOW, WIDE FIELD OF VIEW-TV. 5 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.
NSN 1240-01-651-1682 has DEMIL Code Q. 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.