Peerless-AV's PRG Precision Gear Projector Mount is simplifying the way image alignment is done. The patent-pending precision gear design allows exact tilt and roll image positioning by either simply turning two adjustment knobs with a Phillips screw driver, or use the tool-less option by extending the knobs to adjust by hand. Just set the precision gear to the desired position to secure it in place - it will hold its position even during projector maintenance. With Peerless-AV' PRG Precision Gear Projector Mount, just set it and forget it. No more adjustment screws. No more micro adjustments. No more hassles. All projectors with M8 mounting screws require ACC-M8RI inserts for compatibility with any Peerless-AV projector mount, please refer to the Recommended Accessories.