Countersink drill bit set intended for the creation of pilot holes and countersinks at once. Suitable for use on a range of materials such as wood, plastic, PVC, plywood, rubber and more. Manufactured from 4241 HSS steel. Drill bits fitted with a 1/4" hex shank to be used with any standard sized drill chuck. Hex key supplied to adjust drill bits to accommodate different length screws. Sizes: 2, 2.5, 2.75, 3.25, 3.5mm.