. I had to drill a 1/2" hole in my granite countertop to install the R/O faucet. I've never done anything like this and was afraid of damaging the countertop. This product worked pretty well and I was able to drill the perfect hole in about 20 minutes. I used the drill that came with my cordless drill and was surprised at how easy it was to drill the hole. I submerged the bat in water from time to time to keep it from overheating. Definitely recommend.