I was very impressed with the wrench when I received it as it was the first addition to my grip wrench set; It looked great until I used it for the first time. Cylinder repaired and used to disassemble a trim cylinder on an outboard, 4mm pin fits great; tried because the cylinder head was very tight, started failing a lot when one of the teeth broke off; was so shocked and disappointed. While the finish was nice and I really liked the grip, I would have preferred the manufacturer to harden the tool.