①. The drill bit is surrounded by a spring-loaded guide, which has a window to display the depth of the drill bit when the adjustment is made. ②. Easy to use and install, -handed loading and release can quickly change the position. ③. Suitable for the installation of door hinges. Very suitable for indoor and outdoor doors and windows. ④. positioning, will not move. steel body design, sturdy and durable, anti-rust, easy to use. ⑤. Sawdust will automatically be discharged from both sides of the hole without blocking the drill bit. In order to obtain an accurately centered hole, it can be used for carpenters, cabinets, furniture manufacturers and other woodworking industries. ⑥. Specification: ⑦. Material: High Steel ⑧. The 17-piece combo suit is suitable for various scenarios. ⑨. Size Chart: ⑩. Hinge Drill Size: 1/4" 5mm 13/64" 11/64" 9/64" 7/64" 5/64" ⑪. Package Includes: ⑫. 8 Piece Hinge Drill Bits ⑬. 1 Piece Hex Key ⑭. 8