Materials: high quality HSS steel Size: 4-32mm, 4-20mm, 4-12mm (with 2mm increments) With 2 fluted edges, for cutting fast and smoothly With 3 sided shanks, can prevent slippage when in chuck Can drill perfectly round holes in steel, brass, wood and plastic materials 1 x Wood box 1 x 4-32mm Drill bit 1 x 4-20mm Drill bit 1 x 4-12mm Drill bit