CMMG ZEROED AR15 Bolt Catch Kit Black. The CMMG ZEROED extended bolt catch features dual oversized extended paddles with a tactile machined surface. Steel construction with a durable finish makes for a robustly built component with excellent ergonomics for confident bolt catch operation every time. Specifications for CMMG ZEROED AR15 Bolt Catch Kit: Manufacturer: CMMG Gun Model: AR-15 Fabric/Material: Steel Color: Black Condition: New Package Contents: CMMG ZEROED AR15 Bolt Catch Kit What firearm models does the manufacturer say CMMG ZEROED AR15 Bolt Catch Kit is compatible with? The manufacturer suggests that CMMG ZEROED AR15 Bolt Catch Kit is compatible with AR-15CMMG 55AFF19: ZEROED AR15 Bolt Catch Kit Black