[High-quality materials]: The square hole opening bracket is made of all-aluminum, which is wear-resistant, hard, and long-lasting. [Efficient and convenient]: Professional woodworking tool; the square hole drill adapter bracket can help open square holes in seconds, greatly improving woodworking efficiency, and is a helpful tool for woodworking projects. [Easy to operate]: It is easy to create square holes with this tool. You can quickly install or disassemble it yourself. It is fast and convenient, and even beginners can easily get started. [Universal Design]: Square hole drill bits are designed for universal compatibility and fit 38-43mm electric drill chucks. The clamping diameter is 19mm, which helps ensure accurate and smooth drilling. [Wide Application]: This professional woodworking tool is compatible with most hand drills. It is not suitable for rechargeable drills (lithium series) or bench drills. It is a precision tool for square hole drilling, ideal for creating mortise and tenon joints to achieve strong connections. Color: Silver Material: Aluminum Package Contents: 2 x Square hole opening bracket Note: The package includes only the items listed above. Other products are not included. Note: Light reflection and differences in display screens may cause slight variations in the color of the item shown in the picture compared to the actual product. Measurement may vary by +/- 1-3 cm.