KAK Industry Complete Billet AR15 Lower Receiver - K15Precision CNC machined from aircraft quality aluminumM4 style fire control group pocketType 3 Class II hard coat anodized - deep matte blackUpper receiver tensioning screw includedPictogram selector markings on both sidesAccepts all mil-spec sized lower receiver componentsMilspec buffer tube and bufferKAK lower partsPistol Buffer Tube with Carbine buffer and spring Model: K15Caliber: MULTI