These holesaws are designed to cut metal, mild steel, aluminium, plastic and plasterboard. Progressive tooth strip for a powerful bite and accelerated chip clearance. HSS bi-metal with 8% cobalt alloy for extreme resilience and long lifetime. Power change adaptor for fast and safe attachment and release of the pilot drill bit and holesaw, with just one click. Comes with: 11 Holesaws 1 x Power Change adapter 2 x HSS-G pilot drill bit Kitbox Diameter (mm): 19.0 / 22.0 / 25.0 / 29.0 / 35.0 / 38.0 / 44.0 / 51.0 / 57.0 / 64.0 / 76.0.