Cryptic .233 / 5.56 / .300 AAC Blackout Bolt Repair Kit Manganese Phosphate. 308 WIN / 7.62x51mm / 6.5 Creedmoor) Ejector Ejector Spring Ejector Roll Pin Gas Rings (3) Specifications for Cryptic .233 / 5.56 / .300 AAC Blackout Bolt Repair Kit: Manufacturer: Cryptic Fabric/Material: 4140 Billet Tool Steel Carpenter 158 Steel Caliber: 5.56x45mm NATO .300 AAC Blackout Features of Cryptic .233 / 5.56 / .300 AAC Blackout Bolt Repair Kit Cam Pin (Choice of coating) Extractor (Choice of coating) Extractor Pin Extractor Spring w/ Viton Insert O-Ring (Viton Insert not included with .308 WIN / 7.62x51mm / 6.5 Creedmoor) Ejector Ejector Spring Ejector Roll Pin Gas Rings (3) Package Contents: Cryptic .233 / 5.56 / .300 AAC Blackout Bolt Repair Kit Cryptic CC-RKB-0104: .233 / 5.56 / .300 AAC Blackout Bolt Repair Kit Manganese Phosphate