Easy Installation: The square hole drill bit adapter mortise tool is easy to install and remove, you can quickly install or remove it yourself, fast and convenient. Easy to Use: Professional woodworking tool, the square hole drill bit adapter bracket helps accurate and smooth drilling. Fitment: The square hole drill bit adapter is suitable for hand electric drills, but NOT suitable for bench drills and rechargeable hand drills. Note: The square hole drill bit fixing bracket supports the exposed clamping part of the electric hand drill with a width of about 20mm/0.79inch and a diameter of 38mm-43mm/1.50inch-1.69inch. Please confirm the size carefully. Product size:5.3cmx15cm/2.09inchx5.91inch Colour:Silver Material:aluminum alloy Package Contents: 1 * Drill bit fixing fixture 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.