Tps Arms Ar-15 Bolt Catch Assembly. The bolt catch is designed to work with TPS Arms' proprietary AR bolt and is a direct drop-in replacement. The bolt catch features roll pin teeth that have been hardened to ensure a solid connection and prevent bolt damage. It is made from steel and is black phosphate finished. The TPS Arms Bolt Catch Assembly will fit all mil-spec AR bolts but will require modification to the receiver. Headspace may vary always check with your local jurisdiction. Specifications for Tps Arms Ar-15 Bolt Catch Assembly: Manufacturer: TPS Arms Fabric/Material: Steel Color: Black Length: 6.55 in Height: 0.5 in Package Contents: Tps Arms Ar-15 Bolt Catch Assembly