Complete, fully assembled M4-type upper receiver is ready to install on your lower of choice. Add a rear sight or scope, and you’re ready to go shooting. Perfect for converting a rifle to a carbine, or build a completely new gun customized to your exact requirements. Manufactured in the U.S. from top-quality materials to original Colt specs; each part is gauge-checked during assembly for correct tolerances under MIL-STD 105D. Forged from 7075 T6 aluminum alloy, then hardcoat anodized for added strength and wear resistance. Includes a standard military contour, 16″ barrel with six-groove, 1-9″ twist rifling, plus an A2 gas block/front sight with bayonet lug and 1″ wide sling loop. A2-styl Mfg: High Standard SPECS: Receiver X”X Forged 7075 T6 aluminum, hardcoat anodized, matte black. Barrel – 4140 steel, parkerized finish, black. 16″ (40cm) long. .725″ O.D. at the muzzle. Handguard X”X High-impact polymer, black.