The best protection available against costly outboard motor theft. McGard"s outboard motor locks are designed to lock the bolt that holds the outboard onto the transom of the boat. Simply replace one of the mounting nuts with a McGard locking nut. These outboard motor locks are fully machined from high quality stainless steel and are through-hardened. A free-spinning collar turns if attacked by gripping tools. Fits the following outboard motors: Yamaha 40 hp and larger (2 stroke), Yamaha 30 hp and larger (4 stroke), Honda 40 hp and larger, Suzuki 25-140 hp (2005 and newer).