The DEWALT four cutter countersink provides a clean, professional finish. They are ideal for drilling pilot holes and countersinking in one action and can be used on hard and soft wood, composite board and MDF. The DEWALT DEWDT7607QZ has the following specifications:Accessory Type: No. 12 Pilot Bit and No. 4 Countersink Cutter for use with woodShank: 5/16 inch.