Q Sugar Weasel, Complete Upper Receiver, 223 Remington/556NATO, 13" Threaded Barrel, 1/2X28, 1:7 Twist, Carbine Length Gas System, Matte Finish, Black and Tan, Free Float M-LOK Rail, Adjustable Gas Block, Does Not Include Bolt Carrier Group, Product Finishes, Shade Variations and Other Imperfections Are Normal Due to the Manufacturing Process ACC-SW-556-13IN-UPPER