This is a tool for a professional watch repair person. Built to be used every day  for more than a few lifetimes. Jaxa has no plastic or light metal on it. It is built like a plumbers wrench.  It worked like a charm to turn open the backplate on my waterproof Invicta. When friends and family need to replace a battery in a watch I am prepared for the job. I will have this for the rest of my life.