The XM-73 Reflex Sight was used in the early Bell AH-1 Cobra attack helicopters. This optical aiming sight was used to sight 2.75 inch Folding Fin Rockets fired from the M200A1 Rocket Launcher. Here is an example of a Bell AH-1 Cobra Attack Helicopter at the New England Air Museum. Here is a closeup of the M200A1 Rocket Launcher mounted on an AH-1 Cobra Helicopter..