I needed to drill a 4 1/8" diameter hole in brick trim over 1/2" plywood. I was a bit hesitant when choosing a hole saw due to the many good and bad reviews of different diamond hole saws. I "hold my breath" and bought this device based on "Revain Choice" status and it worked really well. My first thought was that I would need to hire a serious brick drill bit, but I started the hole with a Dewalt 1/2 inch notebook. This hole saw started to cut brick quite well even though I was using it dry. I bottomed out after a few minutes and then chilled the fork to continue. I walked the full width of the brick in about 5 or 6 minutes, although I expected to spend more time doing it. Then I thought how well it would cut through the plywood. no problem. I had a hole cut in less time than I expected. Excellent hole saw, works both ways. Didn't have to cut backwards, but the feature is there when needed.