Retractable starter bit provides accurate centering in less time when cutting tile, stone and glass. Cut clean, accurate holes faster when using the retractable starter bit with Diamond Plus threaded hole saws. With the highly durable retractable starter bit, no pilot holes are required. The 1/4" size fits standard hole saw arbors. No. 49-56-8025: Shank Size: 1/4 In., Length: 2 In., Material: Carbide, For Use With: 7/8" & Larger Diamond Plus Hole Saw, Pkg Qty: 1, Package Type: Box No. 49-56-7135: Shank Size: 3/8 In. Hex, Length: 3 In., Material: Carbide, For Use With: 1-1/4" & Larger Diamond Plus Hole Saw, Pkg Qty: 1, Package Type: Box