Unlike traditional transom savers, Lock N Stow does not tie your outboard to the trailer, which can cause trailer shock when the boat and trailer get out of alignment. This small unit locks the outboard in the forward position without tying it to the trailer. Compact mount constructed of black powder-coated steel with stainless steel pins stores easily in your boat when not in use. Powder-coated steel construction with stainless steel locking pins Fits Mercury engines only Model 3704013 (Mfg # 10107) fits Mercury engines 200-225 Optimax, 225-250 EFI Model 3704111 (Mfg #10108) fits Mercury engines 75-200 Carb and EFI's, 135-175 Optimax