Eight sizes: 1/8 (3mm), 5/32 (4mm), 3/16 (5mm), 1/4 (6mm), 9/32 (7mm), 5/16 (8mm, 11/32 (9mm) & 3/8 "(10mm) Hardened carbon steel shanks with extra-tough M-2 carbide tips; lengths 2-1 / 2 "to 4-1 / 2" Add wall anchors, insert screws, attach studs & install fixtures - must-have set for every homeowner Penetrate concrete, concrete blocks, brick, tile or stone with your power drill