GEISSELE AUTOMATICS LLC MK16 URG-I COMPLETE UPPER RECEIVERS 5.56MM For more than 50 years the famed silhouette of the M16/M4 has only had one major and several minor changes. Barrel lengths and buttstocks have changed, but more or less the evolution of America's right arm has proceeded apace with each generation of warrior making her their own. In that time, the sight of the M16/M4 in the competent grasp of young Americans has meant hope to countless millions of people around the globe. With the advent of the USASOC URGI, that quintessentially American silhouette has changed forever. The Geissele Super Modular Rail MK16 handguard, hammer forged barrel, Mfg: Geissele Automatics