Feature: Note: the width of the exposed clamping part is about 20mm, and the diameter of the exposed part is 38-43mm. If your electric drill does not match the size specified above, please take a picture for reference. Rechargeable (lithium battery series) electric drills are not compatible with this bracket. This product is suitable for older model bench drills and household bench drills. Requirements: The maximum diameter of the bearing circle clamp is 55mm. The chuck height is 10cm. The square hole drill adapter is compatible with drill bits and hand drills, making it a multifunctional tool for various applications. Ideal for woodworking, furniture manufacturing, and related industries. The square hole drill for wood is easy to install and remove, allowing for quick setup and removal, saving time and effort. The square hole drill mounting bracket is made of high-quality metal and plastic materials, ensuring durability and long-term use. Description Name: Square Hole Drill Bracket Set Material: Metal + Plastic Color: Black + Silver Package Contents: 1 x Square Hole Drill Bracket Set Note: Other items not included. Lighting and display differences may cause slight color variations between the image and the actual item. Measurement error allowed is +/- 1-3cm.