The Colt M4 Carbine is the carbine version of the M-16 machine gun issued to United States Military. The Colt M4 Carbine has upper and lower receivers made of high quality aluminum, a steel flash suppressor, threaded muzzle and elevation, front sight adjustable for elevation and rear sight adjustable for windage, standard forearm, bolt catch, removable carry handle, functioning dust cover, and an adjustable telestock.