Expert Quality, for use with most variable speed rotary or stationary pillar drills. Sturdy construction with transparent cowl to retain flying debris whilst drilling especially useful when drilling ceilings etc. Supplied with pilot drill and hexagon key for easy radius adjustment. Cuts plywood, plasterboard, acrylic sheet (up to 23mm depth; 45mm if drilled from both sides), aluminium, brass and sheet metal (up to 1mm depth). Maximum speed for cutting holes up to 115mm diameter is 900rpm; up to 163mm 500rpm. Packed in carrying case and display sleeve.