373001 model code: AD - price is for 1 box, 5ea/box (part# 373001)this item features: -shank type: hex. model code;model Description a a shank diam:1/2 in, used with:hole saws 1-1/4 - 6 in. Diameter ab shank diam:1/2 in, used with:hole saws 9/16 - 1-3/16 in. Diameter AC shank diam:3/8 in, used with:hole saws 1-1/4 - 6 in. Diameter adshank diam:3/8 in, used with:hole saws 9/16 - 1-3/16 in. Diameter.