The square hole drill bit adapter is made of premium high carbon steel, strong and durable, with high hardness and strength, rust-resistant and wear-resistant, not easy to break or deform, providing long-lasting performance. The adapter is precisely designed to be installed on the drill base for secure positioning, offering maximum support for accurate drilling operations. It is compatible with both bench drills and hand drills with a clamp diameter of 38-55mm (1.5-2.2 inches). Please verify compatibility with your drill before purchase. The square hole drill fixing bracket can be installed in seconds, even by beginners, without the need for additional tools, making it easy to install and remove, saving time and effort. This adapter is suitable for standard small electric drills, traditional drill presses, and home drill presses, widely used in woodworking, furniture making, and related applications. Looking for a convenient and efficient way to install or remove a bit? Our square hole drill bit adapter is an excellent choice, helping to secure your drill bit to prevent shaking or movement during operation, enabling a more accurate and efficient drilling process. Exquisite workmanship ensures a smooth surface that will not scratch your hands or equipment. Practical Woodworking Tool: This bracket allows for quick and precise drilling, offering convenience and reliability, making it a great gift for DIY enthusiasts. Product Name: Square Hole Drill Bit Adapter Application: Bench drill and hand drill Color: Silver Material: High-carbon steel Size: Lower inner diameter: 55mm (2.17in), Upper inner diameter: 19mm (0.75in), Clamp diameter: 38-55mm (1.5-2.2in) Package Contents: 1 x Square Hole Drill Bit Adapter Note: The package includes only the items listed above. Other products are not included. Light reflection and display differences may cause slight color variations between the image and the actual item. Measurement error allowed is +/- 1-3cm.