The TacFire SS-RK556 rifle build kit contains- 16" 5.56 Nato, M4 contour barrel/nitride; birdcage flash hider w/crush washer; 15" MLOK free float handguard; AR15 5.56/.223/.300 AAC stripped billet upper receiver w/M4 feed ramps/.556 Mil-Spec charging handle aluminum w/steel latch; dust cover; AR-15 forward assist; AR-15 standard receiver end plate; Mil-Spec/commercial castle nut/steel; buffer tube aluminum; AR 15 3 oz buffer w/tube spring; AR-15 USA made lower parts kit and a AR-15 standard A2 style black pistol grip/A2 style. *Sports South Exclusive.