This Spectre Holesaw Set is supplied in a durable aluminum case, featuring hardened steel teeth for fast, smooth, and clean cuts. It offers advanced heat and wear resistance for prolonged life, making it ideal for cutting wood, plastics, plasterboard, stainless steel, and mild steel. The set includes hex shank arbors for use with 14-30mm and 32-210mm holesaws. The kit contains: 16mm, 20mm, 25mm, 32mm, 40mm, 51mm holesaws; 14-30mm and 32-210mm arbors; and an arbor nut. It is a 9-piece set.