Mfg Item #: 16MBUP-556
HM Defense 16MBUP-556, Upper, Fits AR-15, 223REM/556NATO, 16" MONOBLOC Barrel, Midlength Gas System with Integral Gas Block, 1:8 Twist, Muzzle Brake, Black, Anodized Finish, 10 3/8" Free Float Rail with M-LOK 16MBUP-556