Extension Length: The 1 piece set extends the shank drill bit an additional 8+3/4 inches / The 3 piece set extends the shank drill bit an additional 8+3/4 inches to 5+3/8 inches. Quality Material: 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. Easy to Use: 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. Function: 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. Compatibility: 1 piece set chuck has a 3/8 inch inside diameter for drills with shank sizes of 3/8 inch or slightly smaller. / 3 piece set chuck have 3/8 inch and 2/5 inch inside diameters for drills with shank sizes of 2/5 inch; 3/8 inch or slightly smaller. Made of premium steel, this drill bit extension is sturdy and wear-resistant 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 Quantity:1Pcs set/3Pcs set Colour:As Shown Material:steel<br><br>Package Contents: 1 x Drill Bit Extender 1 x Wrench / 3 x Drill Bit Extenders 3 x Wrenches 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.