The Faithfull 16 Piece Professional Holesaw Set contains the 12 most frequently used holesaw sizes, along with two arbors, an extension and an adaptor. These high speed steel bi-metal saws have specially hardened variable pitch teeth for fast smooth cutting. Bi-metal saws offer increased safety as they will not shatter under load.These holesaws are used by construction workers, builders, plumbers and electricians to cut perfect holes in a wide variety of materials including wood, chipboard, plywood, non laminated plastics, plasterboard and non ferrous metals.Suitable for use in most variable speed power drills.Supplied in a sturdy case for safe and secure storage. Contains: 12 x Varipitch Holesaws: 16, 20, 22, 25, 32, 35, 38, 44, 51, 64, 70, and 76mm.1 x 3/8in Arbor (14-30mm).1 x 7/16in Arbor (32-152mm).1 x Arbor Adaptor.1 x 300mm Extension Bar.1 x Aluminium Case.Additional Information:• Material: Bi-Metal• Pitch: Variable