Trend QR/CS/SET Quick Release 5 Piece Countersink Set Quick release 1/4 inch hex shank for use in quick tool change drills. Five pack. Tool Steel (WS) body with High Speed Steel (HSS) drlll bit for longer life. Countersink ensures screw head is sub-flush and neat. For use in quick chuck drill tools. Can be used to counterbore deeper holes for plugs. For timber, fibre-board and chipboard. Case hardened body for longer life. Adjustable drill bit to suit material thickness. Use in quick chucks and impact drivers. 1 x 2.0mm (5/64") drill countersink 1 x 2.5mm (3/32") drill countersink 1 x 2.75mm (7/64") drill countersink 1 x 3.25mm (1/8") drill countersink 1 x 3.5mm (9/64") drill countersink.