SR-635 Drop In 8" Barrel Upper Receiver Kit & Magazine P/N: 25890 Barrel Caliber Weight Length 8"(20.32 cm) Not Shown SR-635 10" Barrel 6 x 35mm 4.78 lbs (2.16 kg) 24.875'' (63.182 cm) Stock Retracted P/N: 25892 SR635 KAC MUZZLE BRAKE AMBIDEXTROUS CONTROLS MULTI LUG IMPROVED E3...