Abstract: The present invention aims to prevent the theft of air conditioner window units by securing the air conditioner units to windows using a multi-channel clamp adapted to lock the window and air conditioner unit in place. An upward extending channel and a downward extending channel are adapted to slidably accept the top rail of an air conditioner unit and a bottom window sash. The opposing side surfaces of the channel are sufficiently sized to lock the window sash and the air conditioner unit from sliding out of place. The device features a locking thumb screw that locks a window and air conditioning unit in place by forcing the window against the side surface.