Manufactured by Midwest Industries Inc., these free float tubes come in four lengths: Carbine 7 inches, Carbine 10 inches, mid-length 9 inches and full length rifle length 12 inches. With a light weight design these guards are compatible with most gas piston uppers and features the same quality as Midwest's other hand guards; with a no gap monolithic look. Midwest constructed their T-Series float hand guards of 6061 aluminum, hard coat anodized. Features include MIL-STD 1913 rails and are T-Marked for accessory location. Requires minor gunsmithing for installation.