This tool is wobbly and hardly works.  I compared it to my friend's tool (made in Germany and sold for over $50) and they are night and day.  However, considering how often I will use it, it is good enough for me.  If you want a good tool for heavy use, spend more and get a better product.  If, however, you will use it once or twice a year, this might be for you.

Also, do not attempt to use this on a good expensive watch as this tool does not offer the control necessary and you might scratch your watch.