Ergo Grip 9 Piece AR Lower Receiver Spring Kit, Fits AR15, Includes Bolt Catch Spring, Disconnector Spring, Buffer Retainer Spring, Trigger Spring, Magazine Catch Spring, Hammer Spring, Selector Spring, and 2 Detent Springs 4612 Falcon Industries dba ERGO Grip remains family-owned and striving for innovation in developing and manufacturing mission-focused weapons and advanced technology accessories for civilian" law enforcement and government use worldwide.