The World's Best Mousetrap *The KETCH-ALL needs no bait and catches multiple mice in one setting. *Wind trap until winding knob stops. Trap is properly set. *Mice will detect the entrance in the side of the trap with their whiskers. *They will naturally investigate the tunnel and trip the paddle. *Place the KETCH-ALL 1 1/2" to 2" parallel to the wall or set perpendicular to a wall in a space where mice are known to travel. This unit measures: 9 1/4" x 7 1/4" x 5 1/4" high