Name: Drill Chuck & Hex Wrench Specification: 3, 4, 5, 6, 8, 10, 12, 16mm How To Use: 1) Slide correct size drill stop to desired depth on the drill bit. 2) Align locking screw with land (body). 3) Tighten locking screw with included wrench. 4) Remove wrench before use. Great for machinery shaft instruments or on woodworking tools as a bit limit ring. No more wrapping tape around your drill bits! Color: Black Material: Carbon steel Package Contents: 8 x Drill Chuck, 1 x Hex Wrench Only the above package content is included; other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture to be slightly different from the real thing. Measurement allowed error is +/- 1-3cm.