Drywall holesaw.
https://s3-us-west-1.amazonaws.com/h...ck_holesaw.jpg
Previously:
https://www.homemadetools.net/forum/...484#post151173
https://www.homemadetools.net/forum/...455#post142764
https://www.homemadetools.net/forum/...576#post132469
https://www.homemadetools.net/forum/...7815#post86291
https://www.homemadetools.net/forum/...115#post125913
