Makita 194254-0 Keyless Drill Chuck Set For HP2051 HP2051F HP2071 HP2071F 2 Speed Percussion Drill

Makita part number 194254-0 is a 13mm heavy-duty keyless chuck used to replace the standard chuck on several Makita percussion and rotary drills. 
Functions:
Its keyless design allows swapping drill bits rapidly by hand without needing a chuck key.
Specifications:
1.5mm to 13mm capacity and utilizes a standard 1/2" x 20 UNF thread mount.