PROPELLER LOCKS Theft Protection During Use, Storage, and Transit Prop Locks Protect you against expensive propeller theft with a McGard propeller lock, featuring the same patented design as our stern drive and outboard motor locks. A free-spinning collar will spin if attacked by gripping tools without loosening the lock. Constructed of naval brass and hardened stainless steel, once installed our propeller lock offers maximum security for 24-hour protection. 3/4-16 thread fits Alpha1, all Bravo 1 drives (X, XR, XZ), TRS, OMC Cobra and OMC King Cobra.

Don't allow a thief easy access to your propeller. Replaces your standard prop nut and only you can take it off. Fits Bravo One, XR, XZ, Alpha, TRS, OMC Cobra, and New Mercury SSM II - IV, Johnson and Evinrude outboards.