Made of naval brass and hardened stainless steel
Free-spinning collar turns w/o loosening the lock
Important Protection For Your Stern Drive! Made of naval brass and hardened stainless steel, McGard locks feature a free-spinning collar that turns if attacked by gripping tools, without loosening the lock. Simply replace one of the nuts holding the stern drive and tighten with the special key tool provided. Fits Mercruiser Alpha & Bravo and OMC Cobra & King Cobra stern drives. 7/16" thread.