The 1 piece set extends the shank drill bit an additional 8+3/4 inches. Our drill bit extensions are made of quality steel material, with sturdy structure, not easy to break or damage. Precision grinding and polishing ensures that it can be used for a long time. The drill bit extension includes two fixed screws and hexagonal spanner. To secure the shank in place, tighten these screws with the hexagonal spanner, easy to use. Our drill bit extension allows you to extend any shank drill bit extra long to help you drill flat holes with a standard drill bit or start a deep hole turning project, such as on larger vases or containers. 1 piece set chuck has a 3/8 inch inside diameter for drills with shank sizes of 3/8 inch or slightly smaller. Made of premium steel, this drill bit extension is sturdy and wear- for long-term use. It is great for extending any shank drill bit extra long to help you drill flat holes with a standard drill bit or start a deep hole turning project. Fix Screw: The drill bit extension is designed with fixed screws, which helps secure the shank in place for efficient extending working. Product Name:Drill Bit Extension Type:A:1PCS Set Colour:As Shown Material:Metal Package Contents: 1 x Drill Bit Extender 1 x Wrench Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.