Inca Corp. manufactures a lift system that lowers a projector out of the ceiling into a room for use,  then conceals itself back into the ceiling, at the push of a button. Choices of control options include simple rocker switch, one-button radio remote, Infrared Transponder Control, and 12 VDC or dry contact closure for touch-screen use.   Units are available in two standard sizes. Custom dimensions and lift capacities are available. Machines are fabricated from aluminum.