The Front,spectacle, cataloged under National Stock Number 6540-00-497-2457, is classified within Federal Supply Class 6540 (Ophthalmic Instruments, Equipment, and Supplies) of the Medical, Dental, and Veterinary Equipment group. Government technical data includes 7 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active. Unit of issue: EA.
| Parameter | Value |
|---|---|
| NSN | 6540-00-497-2457 |
| Item Name | Front,spectacle |
| FSC / FSG | 6540 / 65 — Ophthalmic Instruments, Equipment, and Supplies |
| Status | ACTIVE |
| Style Designator | KEYHOLE BRIDGE WITH ADJUSTABLE ROCKING NOSE PADS |
| Bridge Width | 20.000 MILLIMETERS MM |
| Nondefinitive Spec/std Data | I TYPE |
| Eye Wire Maximum Vertical Inside Diameter | 35.000 MILLIMETERS MM |
| Eye Wire Maximum Horizontal Inside Diameter | 46.0 MILLIMETERS MM |
| Color | BLACK |
| End Piece Type | 2 BARREL |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Unit of Issue | EA |
| Reference | Meaning |
|---|---|
| MILS36497 | 4/1 Identification reference U.S. Government activity |
NSN 6540-00-497-2457 is a Front,spectacle, classified under FSC 6540, Ophthalmic Instruments, Equipment, and Supplies. Status: active.
2 possible matches (shared part number, not a government interchangeability claim): 6540-00-497-2458, 6540-00-497-2462. Verify interchangeability with system specifications before substitution.
Key specifications for 6540-00-497-2457: Style Designator: KEYHOLE BRIDGE WITH ADJUSTABLE ROCKING NOSE PADS; Bridge Width: 20.000 MILLIMETERS MM; Nondefinitive Spec/std Data: I TYPE; Eye Wire Maximum Vertical Inside Diameter: 35.000 MILLIMETERS MM. 7 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.