This is the m1a2 Tank Urban Survival Kit as detailed on wikipedia and elsewhere: http://en.wikipedia.org/wiki/M1_Abrams#Tank_Urban_Survival_Kit_for_M1A2 The features added are a remote weapons station, rear anti-rpg slat armor, reactive skirt armor tiles and tank/infantry telephone. http://www.cs.ndsu.nodak.edu/~pratt/