9-piece high speed bi-metal steel hole saw kit for cutting mild steel, aluminum, plastic, and plasterboard Ideal for carpentry, construction, plumbing, and more Constructed with HSS-M3 bi-metal material with a powder-coated finish for smooth cuts and durability Durable carrying case for storage and easy portability Includes 6 hole saws in sizes 25/32" (20mm), 1" (25mm), 1-3/8" (35mm), 1-9/16" (40mm), 2" (51mm), and 2-11/16" (68mm); a 1/4" hex arbor with 75mm pilot drill to connect 14-30mm hole saw; a 7/16" hex arbor with 75mm pilot drill to connect 32-152mm hole saw; and a hex key