Make it Snappy Tools 3 Piece Tapered Plug Cutter Set: Hex Shank Drill Bits: Amazon.com: Tools & Home Improvement
Milescraft 3-Piece Tapered Plug Cutter Set - 1/4-In, 3/8-In, and 1/2-In - Steel Construction - Quick Change Compatible in the Woodworking Tool Accessories department at Lowes.com