Vibra-Stop backing pads substantially reduce vibration on large and small boats. This is accomplished by reducing the pressure pulses produced from the outboard pushing on the boat, while also reducing circular vibration transferring from the engine mounts. Vibra-Stop pads absorb vibration and do not retransmit it. If your motor has slotted lower mounting holes order aluminum keys for your motor. Also, consider our bushing kits which further reduce resonance and vibration by acoustically isolating the mounting bolts on an outboard motor. Vibra-Stop products make your boating more pleasurable by changing the whole feel of your boat.