- The Telescope, M105 is intended for use as a component of the secondary direct fire control system of the 90mm Gun, Tank, M48 Series; the Telescopes, M105C, M105D and M105E1 are intended for use as components of the secondary direct fire control system of the 105mm Gun Tank M60 and M60A1. The Telescope M105F is used for direct fire of the 165mm Gun in the Combat Engineers Vehicle, T118E1. These instruments employ a complex optical system having eight power, a 7.5° field of view, and utilize two ballistic reticles calibrated for ranges in meters for different type ammunition, either of which may be shifted into the focal plane. The telescopes are designed with an articulating point about midway between the objective and eyepiece to permit the objective tube of the telescope to elevate coaxially with the gun while the eyepiece movement is relatively stationary.