11pce Holesaw Set. High carbon steel holesaws: 19, 22, 30, 32, 38, 44, 54 & 64mm 2pce arbors 6.35mm (1/4") shank, chuck 6.35mm (1/4") with 6mm HSS drill, for use with 19mm to 30mm holesaws 9.5mm (3/8"), chuck 9.5mm (3/8") with 6mm HSS drill, for use with 32mm to 64mm holesaws, 1pce hex key to fit