Features Versatile Fit: The 9mm round shank design ensures compatibility with standard chucks, making this twist step drill bit set a versatile addition to your toolbox for various drilling needs. Precision Holes: With a small tip featuring a clearance hole for screws, this drill bit set creates precise and clean holes for screw shanks, ensuring a secure fit for your pocket hole joinery. Flat-Bottomed Design: Designed to make flat-bottomed holes, the large diameter bit is ideal for creating strong and professional-looking joins with your pocket hole drill jig guide kit. High Speed Capability: Engineered for optimal performance with high-rpm drills, this set is recommended for use with corded drills to achieve efficient and smooth drilling for your carpentry projects. Complete Accessory Kit: This twist step drill bit set comes equipped with a wrench and limit ring, providing you with the necessary tools for quick adjustments and precise depth control during drilling. Features:It can work with standard chucks of 9mm diameter.Small tip includes clearance hole for screw shankLarge diameter creates flat-bottomed holeRecommended for use with corded high-rpm drillsPerfect for use with pocket hole guidesCome with wrench and limit ring Specification:Big head diameter: 9mmSmall head diameter: 4.2mmPurpose: used for drilling wood Package list:1 * bit1 * small wrench1 * location ring Package List