Quality Materials: The drill chuck is made of high quality metal, the keyless drill chuck is strong and durable for long working hours. Specification: Drill Chuck Diameter: 43mm, Length: 71mm, Link Size: 1/2-20 UNF, Clamping Range: 1.5~13mm. Ergonomic Design: Keyless and self-tightening type design is more in line with human engineering. The chuck can hold the drill bit firmly and sturdy, not easy to loosen. Easy to Use: Multi-purpose self-tightening drill chuck is easy to install and disassemble, making it easier and less laborious. Ideal Accessory: Wide range of collet sizes from 1.5 to 13mm, suitable for many types of drill bits. Following human engineering., Suitable for long-term work.