They were cheap and barely worked. I bought two for two different cars and clutches. In both cases, the holes do not match. I was able to insert a pin into the one I installed, but I had to force it through. If they were metal, this probably wouldn't be possible. I'll probably just cut off the part that's protruding into the hole, but I don't have to. My guess is that the width of the reinforcement around the hitch hole is in contact with the sloped sides and prevents them from slipping. completely indoors.