You'll Want One Of These For Your Tool Box. Attaches To Any Electric Drill Motor, And You Can Make Different Size Holes From 1 - 5". Adjustments Of The Size (scaled) Is Done With 6mm Hex Key Wrench. (Included). Made Of A Strong Alloy, Comes With Hex Key And Replaceable Center Drill Bit.

Built in scribers on each side adjust from 1 inch up to 5 inches

You can insert the 10mm shank into most electric drills-5-3/4 X 6 Inches-weighs 13 ounces

This unit io made of a strong alloy material that is made to work hard for you

A hex key wrench is included to be sure you get the setting tight so they don't shift position

This unit is made in such a way as to ensure a perfect circle hole everytime