Features: Caliber: 5.56 NATO / .223 REM Barrel Length: 20" Barrel Material: Phosphate Chrome Lined Barrel Thread Pitch: 1/2 x 28 Twist Rate: 1:7 Gas System: Rifle Length Lower Receiver Material: 7075 Aluminum Alloy Model Marking: XM15-E2S Lower Receiver Logo: 50th Anniversary White Upper Receiver Material: 7075 Aluminum Alloy Upper Receiver: A2 Bolt Carrier Group Finish: Chrome Lined Phosphate Bolt: MPI & HPT Tested Handguard: A2 Heat Shields Stock: A2 Fixed Stock Grip: A2 Pistol Grip Trigger Guard: Mil-Spec Trigger Guard Trigger: Mil-Spec Safety Selector: Mil-Spec Selector Muzzle Device: A2 Flash Hider Magazine: BFI Aluminum Magazine Capacity: 30 Round Front Sight: NON F-Marked A2 FSB Rear Sight: 8/3 Fixed Carry Handle Proudly Made In: U.S.A.