UPDATE 6/28/16 Originally I had given this 4 stars but after having this since October 21, 2015 it has gone from hard to use to impossible to use. I have tried several lubricant sprays and greases but nothing works for long, this does not work well for a boat trailer where the coupler gets wet frequently as it just starts to corrode and get hard to use, my original coupler lock was still going working great when I maimed it and this one is now dead and I am looking for a replacement.  I had expected it to last at least a couple of years of use and it hasn't lived up to that expectation.