Cam-action neoprene plugs snap shut to form stopper for Livewells or Baitwells. Clockwise turn of the handle tightens plug, and the lever flips down to lock. So simple! Cam-action neoprene plugs snap shut to form stopper for livewells / baitwells Clockwise turn of the handle tightens plug Lever flips down to lock Ideal for livewell drain Note: Not for use with chemicals or fuels 4 sizes to choose from for I.D. thru-hull