Features:_x000D_ _x000D_ The chuck can hold the drill bit tightly and sturdy,not easy to loose. _x000D_ Durable and has long service life,suitable for long time work. _x000D_ Easy to install and disassemble,more convenient and labor-saving. _x000D_ Large range of clamp size which range from 2~13mm,suitable for many kinds of drill bit. _x000D_ Keyless and self-tighten type design is more in accordance with human engineering. _x000D_ _x000D_ Specification:_x000D_ Diameter:43mm/1.69in_x000D_ Length:58mm/2.28in (3-5mm tolerance)_x000D_ Connection Size:1/2-20UNF_x000D_ Clamp Range:2 ~ 13mm / 0.04 ~ 0.51in _x000D_ _x000D_ Package List:_x000D_ 1 x Drill Chuck_x000D_ _x000D_ _x000D_ _x000D_ Note:_x000D_ Before purchase, it is necessary to verify whether the connecting thread of your electric drill is 1/2-20UNF. (1/2 - 20 is the definition of thread specification. Specification: 1/2; number of threads (T): 20. UNF, UN is the standard code of inch thread, and F is fine thread).