This complete bolt group will fit Steyr AUG .223 Rem, 5.56x45mm and .300 Blackout bullpup rifles. The assembly includes a black finished steel right-handed bolt, stainless extractor, extractor spring and pin, ejector, ejector spring and pin, control bolt and control bolt retaining pin. Includes: Right or left Handed BoltExtractorExtractor Spring Sub AssemblyExtractor PinEjectorEjector SpringEjector Retaining PinControl BoltControl Bolt Retaining Pin Steyr Arms AUG Right Hand Bolt 1200040570E