Daniel Defense M4A1, Upper, Complete Upper Receiver, 5.56 NATO, 14.5" Pinned (16" OAL), Daniel Defense M4A1 FSP Rail Interface System Rail, Carbine-Length Gas System, Surefire SF3P Flash Hider, M16 Profile Bolt Carrier Group, Anodized Finish, Flat Dark Earth and Black 23-004-09376