The Muffler,exhaust, cataloged under National Stock Number 2990-00-689-3299, is classified within Federal Supply Class 2990 (Miscellaneous Engine Accessories, Nonaircraft) of the Engine Accessories group. The manufacturer of record is Caterpillar Inc Div Caterpillar Defense. Government technical data includes 14 specifications, cited from the U.S. Government catalog. The record lists 2 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 2990-00-689-3299 |
| Primary Part Number | 8S905 |
| Item Name | Muffler,exhaust |
| FSC / FSG | 2990 / 29 — Miscellaneous Engine Accessories, Nonaircraft |
| Manufacturer | Caterpillar Inc Div Caterpillar Defense |
| Status | ACTIVE |
| Operating Position | UNIVERSAL |
| Inlet Location | CENTERED ON END OF BODY |
| Coolant Type | AIR |
| Design Type | DRY |
| Overall Diameter | 6.000 INCHES NOMINAL IN |
| Inlet Projection Length | 5.250 INCHES NOMINAL SINGLE INLET IN |
| Outlet Outside Diameter | 4.250 INCHES NOMINAL FIRST OUTLET IN |
| Inlet Connection Type | UNTHREADED SINGLE INLET |
| Body Shape | ROUND |
| Inlet Inside Diameter | 6.000 INCHES NOMINAL SINGLE INLET IN |
| Material | STEEL LOCATION NOT OTHERWISE SPECIFIED |
| Outlet Projection Length | 2.250 INCHES NOMINAL FIRST OUTLET IN |
| Outlet Connection Type | UNTHREADED FIRST OUTLET |
| Outlet Location | CENTERED ON END OF BODY |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
NSN 2990-00-689-3299 is a Muffler,exhaust, manufactured by Caterpillar Inc Div Caterpillar Defense, classified under FSC 2990, Miscellaneous Engine Accessories, Nonaircraft. Status: active.
NSN 2990-00-689-3299 has 2 manufacturer part numbers on file: BS0905 (Caterpillar Inc Div Caterpillar Defense), 8S905 (Caterpillar Inc Div Caterpillar Defense).
Key specifications for 8S905: Operating Position: UNIVERSAL; Inlet Location: CENTERED ON END OF BODY; Coolant Type: AIR; Design Type: DRY. 14 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.