CMC Triggers Complete Lower Receiver Parts Kit for AR-15 is a great addition to your AR15 build. From amateur gun builder to seasoned expert gunsmith, this lower parts kit is for you. *NOTE: Fire control group & grip NOT INCLUDED PARTS INCLUDED Bolt Catch Bolt Catch Plunger Bolt Catch Spring Bolt Catch Roll Pin Mag Release Mag Release Button Mag Release Spring Buffer Retainer Spring Safety Buffer Retainer Safety Detent Spring Safety Detent Trigger Guard Trigger Guard Roll Pin Take-down Detent Springs Take-down Detent Take-down Pins