It works when its been modded to your design, doesnt come with instructions. it can run on 12vdc or any range of DC volts between 12 to 25 DC. I removed the end screws and drilled complete thur the housing so i could properly mount to a wood post. also drilled more holes in the strike plate so it doesnt move, only one middle hole is drilled. also, moved the way the wire enters the unit so it comes out from the bottom, (drilled hole) instead of the side, gooped up other openings to make it weather proof and removed the little light on it advertising that its on. power drain is about 1/2 amp or less.