Windham Weaponry Lower Parts Kit This complete Windham Weaponry Lower Receiver Parts Kit will give you everything needed to build up a stripped Lower or keep your AR functioning in the toughest conditions. All highest quality parts, this kit includes: AR Hammer with J-Pin Hammer Spring AR Safety Selector Lever Safety Detent Safety Detent Spring Bolt Catch Bolt Catch Spring Pin Bolt Catch Plunger Bolt Catch Spring Magazine Catch Magazine Catch Spring Magazine Catch Button Takedown/Pivot Pin Detents (2) Takedown/Pivot Pin Springs (2) Pivot Pin Takedown Pin AR Trigger Trigger Spring AR Disconnector Disconnector Spring Trigger Guard (Aluminum) Trigger Guard Spring Pin Hammer/Trigger Pins (2) Pistol Grip Pistol Grip Screw Pistol Grip Washer Buffer Retainer Buffer Retainer Spring