Features 1、Premium Quality Material: Made of hard alloy material, high hardness and durable. This set of countersink drills has super cutting power and fully sharp edges, fast drilling speed and long service life. 2、Shank Size: 8mm; 5 Drill Bit Sizes: 2.8mm/3.0mm/3.2mm/3.5mm/4mm; total: 5 pcs to meet your various needs. 3、Bearing-Equipped Design: The mounting of bearings ensures controlled drilling without damaging the wood, and prevents unwanted scratches or grooves. 4、Easy to Install: ① Unscrew the drill counterclockwise from the limiter; ② Unscrew the screws with an Allen wrench; ③ Determine the length of the hole to be drilled, and then tighten the screws with a wrench; ④ Screw the drill clockwise from the head to start working. 5、Wide Compatibility: Suitable for solid wood board, PVC, density board and other materials to open holes, can be used with row drilling machine, bench drill, hand drill, lithium electric drill. (Note: 12V lithium electric drill torque is too low, not recommended!) Specification Specifications: Quantity: 5 Pcs / 6 Pcs (Optional) Material: Steel Shank Diameter: 8mm Blade Length: 11mm Blade Diameter: 10mm Package Weight: 460g / 1.01lb Package Size: 19.6 * 14.9 * 4.9cm / 7.72 * 5.87 * 1.93in Package List Package List: 5 * Countersink Drill Bit 1 * Storage Box