For milling machine， lathe， drilling machine， wood working machine.
The shank with scrw can be tight and flex for you.
Should work with power drill， here is not included.

Specifications:
Capacity:0.6-6.5mm
Mount Thread:3/8-24UNF
Interior Hole Diameter 6mm/ 0.24"
Exterior Hole Diameter Small: 30mm/ 1.2"， Big: 23mm/ 0.9"
Total Height 4.7cm/ 1.85"
Chuck Key 55 x 35mm/ 2.2" x 1.4" (L*W)
Main Material: Metal
Color Black， Silver Tone

Package Included:
1 x 0.6-6.5mm Drill Chuck
1 x Chuck Key
1 x 1/4" hex shaft