The M123 Gunner Armor Protection system consists of a roughly torso-high titanium-carbon nanotube guard around the side and rear of the Warthog's gun turret, as well as lengthened gunshield with a central bulletproof plexiglass panel over the central gap in the gunshield to better protect the gunner's head from fire coming directly towards him. While the system does offer more protection for the gunner, it still leaves the back of their head and upper torso exposed. Because of this limitation, it is often said that the acronym, GAPS, is appropriate as the armor kit has wide gaps in it's defenses. Variants of the system exist for the M41 LAAG, the M68 Gauss Cannon, the SC-HE 102mm Missile Launcher, and M79 Multiple Launch Rocket System.