Peerless' PRG Precision Gear Projector Mount is changing the way image alignment is carried out. The patent-pending precision gear design provides exact tilt & roll image positioning with a simple turn of a knob. Once the precision gear is set to the desired position it stays securely in place. It will not shift during projector maintenance, bulb replacement, & will not loosen or change alignment due to vibration, accidental bumping etc. With Peerless' PRG Precision Gear Projector Mount the installer sets it & forgets it.