American Built Arms Company AB Arms AR-15 Parts Kit Small. With this Small Parts Kit on hand you'll always have the parts you need to keep your rifle running smoothly. These high-quality parts are manufactured to precise tolerances to ensure a correct fit with your 5.56 AR-15/M16 rifle. This convenient Small Parts kit contains all the parts needed to keep your 5.56 AR-15/M-16 rifle like new. Specifications for American Built Arms Company AB Arms AR-15 Small Parts Kit: Manufacturer: American Built Arms Company Gun Model: AR-15 Package Contents: American Built Arms Company Ab Arms Ar-15 Small Parts Kit Firing pin retaining pin Ejector Ejector spring Ejector pin Extractor spring with insert Extractor axle Gas rings (3) O ring (donut) American Built Arms Company ABAARSP: AB Arms AR-15 Parts Kit Small