Extra Long Hole Saw Bit Extension for Hole Saw Arbor 22" Long 7/16 Drill Bit Extension Kit 7/16" Hex Male To 7/16" Hex Female Drill Extension 7/16" (11mm) Hex Arbor Hole Saw Extension Set Hex Key Inc 22 Inch Drill Bit Extension Shank 7/16 in Hex Extension Drill Extension Bit Holder 7/16" Hex Male to 7/16" Female Hex Shank Extension allows you to Drill Deep Holes in Concrete Wood and Brick Drill Long Reach Extension for Drill Bits with 7/16" Hexagonal Shaft 12 inch Extension Drill Bit Heat Treated Hex Drill Extension Hole Saw Drill Extension Hex Key Included to Keep 7/16" Hex Shafts Secured in Female End Also fits most Arbors to Tighten Pilot Drills 22 inch Hole Saw Extension bit extension 22" Long Bit Extension with 7/16 in Hexagonal Ends These Hole Saw Arbor Extension are a 12 inch Extension Bit with 7/16" Hex Male to 7/16" Hex Female. Use with 7/16" (11mm) Hex Arbor for Holesaws to Drill Deep Holes in Concrete Brick and Wood Hex Key Included to Lock Arbor in place. Heat Treated 12 inch Hexagonal Extension Fits Any 7/16" Hex Shaft Hole Saw Arbor - Hex Screw Secures and Tightens Hex Shaft of Arbor or 7/16" Drill Attachment. Use Arbor Extension Bit with our Tungsten Carbide Grit Edge Hole saws To Drill Deep Holes in Concrete Masonry And Brick Walls. Note 3/8 inch Hex Also available so make sure you measure and order the correct size for your hole saw Arbor or drill or there will be wobble with an incorrect fitting hex. Plumbers Tools for Drilling Holes for Pipes to go through walls. and Electricians Tools for Drilling Holes through walls for electrical wires and conduit.