This tool worked great. Until it exploded and stopped working. I used it to punch a few extra holes in an old computer case for new ports to be cut; was about halfway through my project when it just broke. The underside of the shaft that the router goes through broke off completely and now it doesn't work anymore. It was a pretty dangerous and spectacular mistake to be sure she really needs to reinforce that part so it doesn't, it's also a very inefficient and painful tool that requires repetitive pressing motions over and over to break off a small rectangle no thicker than a few millimeter is.