This is a really nice X belt holder and tensioner but I had a hard time to get it done. First, it was not possible to slide the stopper, it stuck in the left side. I practically had to shave the groove off the back side, you don't need that anyway. Second, the left side is a bit too tight, you could loosen it a tiny bit, I had to use a screwdriver to shove it in. Again, this is definitely a winner, thank you.