This Starrett Holesaw Kit is ideal for cutting stainless and mild steel sheeting, plasterboard, wood and thin plastics. The holesaws are constructed from heat-resistant, hardened steel with constant pitch teeth for exceptionally smooth cuts. They come completely assembled, ready for use. A safety stop collar at the base of the holesaw prevents travel beyond the holesaw depth. Supplied in a sturdy EVA carry case with the following: 7 x Holesaws: 16, 20, 25, 29, 30, 32 and 38mm 1 x A18 Dual Hex Chuck