I installed a Thule roof system myself and after seeing how easy it would be for someone to just snatch it off my roof, I purchased these. It's somewhat of a racket since they are so expensive but it works like a charm. the holes in the brackets just punch right out and these little locks slip right in. Works like a charm and no one can steal my VERY expensive roof system without a little work. One thing to think about - if you have a Thule box, you might want to get six of these so EVERYTHING can be the same key. I didn't think of that and now have two keys - one for the four brackets and one for the roof box. oh well - it all works well. The only down side is the cost.Get more detail about Thule Lock Cylinders (6 pk) - 512.
