Premium Material: The square hole drill fixed holder is made of cast steel, sturdy. If you are looking for a versatile and efficient way to quickly install or disassemble drill accessories, then look no further than the square hole drill adapter. Note: If you store it in a humid environment for a long time, it may cause some rust on the surface, which can be improved by simply wiping some protective oil. 【Drill Mortise Attachment】The square hole drill adapter is suitable for bench drills and hand electric drills, clamping diameter between 38-55mm, allowing for effortless installation and use. Suitable for all sizes of square hole drill bits. 【Square Hole Fixing Bracket】The square hole drill adapter is for bench drill, drill press, mortising machine, hand drill. The square hole drill adapter is perfect for woodworking, furniture manufacturing and other related industries. 【Mortise Accessories for Bench Drill】The mortise fixing bracket is easy to use, you can quickly install or remove it by yourself, saving you time and effort. 【Efficient and Accurate】Mortise fixture designed specifically for square hole drill bits, the adapter ensures precise and smooth drilling operations. Perfect for drilling on the edge of a board or on round stock. Note: The square hole drill bit and electric drill are not included in the package.