[Durable Material]: The square hole drill fixed bracket is made of high quality cast aluminum material, wear resistant, high hardness, sturdy and durable. [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 a diameter of 38mm-43mm/1.50inch-1.69inch. Please confirm the size carefully. [Easy to Use]: Professional woodworking tool, the square hole drill bit adapter bracket helps accurate and smooth drilling. [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. Please note:The physical slightly color difference or difference, does not affect the use, please do not mind, thank you Colour:As Shown Material:aluminum Package Contents: 1 * Square Hole Drill Bit Adapter 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.