Description: Premium Material: The square hole drill bit fixed bracket is made of Aluminum material, which is wear resistant, sturdy, and not easy to breakSize Compatibility: The Square Hole Drill bit Fixing bracket can accommodate most hand drill with a clamping part width of around 20mm and a diameter of 38-43mm as shown in the picture. Please note that this bracket is not suitable for () drillBench Drill Mortise Accessories: The square hole drill bit adapter converter is easy to install and remove, you can quickly install or remove it yourself, which is fast and convenientNote: Square hole drill bit adapter, products do not include square hole drill and electric drillWide Application: The square hole drill bit adapter bracket is great for woodworking enthusiasts and professionals, furniture making, and other related industries, ensuring accurate and smooth drilling Specification: Product size: 5.3cmx15cm/2.09inchx5.91inchMaterial: Aluminum Color: Silver Package Includes: 1 Square Hole Drill Bit Adapter 2 Washers 2 Wrenches Note: Please allow slightly errors due to manual measurement and different monitors.