I like the design. But it doesn't work. He is well built and strong. It's very dangerous! After the hole is drilled and the reaming begins, the tool dives in and the drill you use pops out of your hands. I'm a big guy with a 1/2 corded drill. This can be great when drilling foam board. Please note this is a size 5/8 review. I also have a size 1/2 and it worked fine on the hole I tried it on.