I'm looking to find the drill bit with the blade and guide that Richard used to bore out the PVC pipe in Season 10 Episode 8 of Ask This Old House - looking to get one for my father! Any suggestions on what it's actually called would be helpful too!

Season 10, Episode 8, "Sink Drain, Floor Fix" about 6 minutes into scene 2

you can email me at: egardner820 at gmail .com