[Material]: The square hole drill fixed bracket is made of high-quality cast aluminum material, wear-resistant, high hardness, sturdy and durable. [Fitting]: 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 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 achieve accurate and smooth drilling. [Easy Installation]: The square hole drill bit adapter mortise tool is easy to install and remove, allowing quick setup and removal, fast and convenient. Please note: Slight color difference may occur due to lighting or display settings, which does not affect usage. Color: As shown Material: Aluminum Package Contents: 1 x Square Hole Drill Bit Adapter Only the above package content is included; other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture to vary slightly from the real thing. Measurement may have an error of +/- 1-3cm.