[Special design]: This keyless chuck has a self-tightening design, which makes the chuck more reliable when tightening the tool [Saving time and effort]: The inner thrust bearing helps convert torque applied by the handle into a larger clamping force [Easy to Use]: The self-tightening chuck adopts a more ergonomic design for easy operation and quick change [Fitment]: The hand drill chuck is suitable for impact drills 1050W or more [Specification]: Connection size: 1/2-20UNF; Clamp chain: 2-13mm/0.04-0.51in; Diameter: 43mm/1.69in Features: The chuck can hold the drill bit firmly and sturdy, not easy to loosen. Durable and has a long service life, suitable for long time work. Easy to install and disassemble, more convenient and more economical.Wide range of collet sizes from 2-13mm, suitable for many types of drill bits.The keyless and self-tightening type design is more in line with human engineering. Specification: Diameter: 43mm/1.69in Length: 71mm/2.8in Connection size: 1/2-20UNF Clamping range: 2~13mm/0.04~0.51in Package list: 1 * chuck drilling