VERSATILITY: Bosch hex shank countersink bits feature adjustable depths and provide precise, clean pilot holes in wood, plastic and composite materials 3 in 1: Drill, Countersink and Counterbore in one step UNIVERSAL FIT: The Bosch SP515 countersink set fits all Bosch and competitive brands drill/drivers USE WITH: For use with Allen wrench (included in set); the hex shanks fit 3/8 in. and 1/2 in. corded and cordless drills ACCESSORIES: Replaceable bits offered (sold separately)