Extension Length: 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: 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., Weight: 1.38229838274 pounds, Manufacturer: Boddceto