TOTAL SHIT! The locking screw made assembly difficult. The whole thing, as others have said, BENT the moment it hit the wood, the center guide bit felt dull as I drove a 3/4" thick shelf into the board which I tried to punch a hole in to drill eventually i was able to do it all that way but it took a full minute or 2 and the cut is rough and the bit is scrap at the moment just rubbish luckily i only had to cut one size hole and it was cheaper than buying a properly sized hole saw from a quality company to accomplish its mission.