Fully hardened high carbon steel. Self feeding point for a safe start and accurate drilling. 2 adjustable cutters for holes from 22-45mm and 45-76mm. For drilling large clean holes in softwood, medium hardwood, particle board, plasterboard, plastics and fibreglass. For use with drills, drivers and hand braces. Fully hardened high carbon steel. Self feeding point for a safe start and accurate drilling. 2 adjustable cutters for holes from 22-45mm and 45-76mm. For drilling large clean holes in softwood, medium hardwood, particle board, plasterboard, plastics and fibreglass. For use with drills, drivers and hand braces.