I'm a repeat-buyer of trimax and have another that is not stainless and still functions perfectly.  For the extra couple of bucks it made perfect sense to upgrade to stainless for my other SUV.  The o-rings on the shaft-side of the lock, as well as the rubber cover over the seal keeps the lock literally maintenance-free.  Go ahead! Submerge this lock under water while backing your boat down the ramp.  It'll take anything you throw at it.  Smooth mechanicals and positive lock safety built-in make this lock a must-have.