The Adapter,muffler,threaded, cataloged under National Stock Number 2990-01-123-6909, is classified within Federal Supply Class 2990 (Miscellaneous Engine Accessories, Nonaircraft) of the Engine Accessories group. The manufacturer of record is Riker Products Inc. 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 2990-01-123-6909 |
| Primary Part Number | NP300 |
| Item Name | Adapter,muffler,threaded |
| FSC / FSG | 2990 / 29 — Miscellaneous Engine Accessories, Nonaircraft |
| Manufacturer | Riker Products Inc |
| Status | ACTIVE |
| General Characteristics Item Description | STEEL; 6.000 IN. LG; 3 IN. OD; 3.000 IN. NPT IN |
| 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 |
|---|---|
| NP300 PRIMARY | Riker Products Inc (USA) |
| Reference | Meaning |
|---|---|
| NP300 | 3/9 Design control — primary reference Riker Products |
NSN 2990-01-123-6909 is a Adapter,muffler,threaded, manufactured by Riker Products Inc, classified under FSC 2990, Miscellaneous Engine Accessories, Nonaircraft. Status: active.
NSN 2990-01-123-6909 has 1 manufacturer part number on file: NP300 (Riker Products Inc).
1 possible match (shared part number, not a government interchangeability claim): 5306-01-317-2534. Verify interchangeability with system specifications before substitution.
Key specifications for NP300: General Characteristics Item Description: STEEL; 6.000 IN. LG; 3 IN. OD; 3.000 IN. NPT IN. 1 specification is 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.