The square hole drill bit adapter is made of premium high carbon steel,strong and durable,with high hardness and strength,rust-proof and wear-resistant,not easy to break and deform,and will you for a long time. The square hole drill bit adapter is precisely designed and can be installed on the base of the drill to fix position,and you can get the maximum support to accurate and drilling operation. The square hole drill fixing bracket can work with both bench drill and hand drill with 38-55mm/1.5-2.2 inches clamp diameter. Please make it fits your drill before purchasing. The square hole drill fixing bracket can be installed in a few seconds even if you are a beginner,no other auxiliary tools are needed,easy to install and remove,saving you time and effort. The square hole drill bit adapter is suitable for ordinary small electric drills,old-fashioned drill presses,and home drill presses,widely used for woodworking,furniture making,and other related industries. Are you looking for a convenient and efficient way to quickly install or remove a bit attachment? Our square hole drill bit adapter would be a great choice It will help you fix your drill to prevent shaking and moving when drilling,and gives you an accurate and faster drilling process. Exquisite Workmanship: The square hole drill bit adapter is carefully designed with a surface,and will not scratch your hands or drill when working. Practical Woodworking Tool: Our square hole drill fixing bracket can help you drill hold accurately and quickly,very convenient and practical,and a great gift for . Product Name:Square Hole Drill Bit Application:bench drill and hand drill Colour:Silver Material:High-carbon steel Size:Lower inner diameter:55mm/2.17in, Upper inner diameter:19mm/0.75in, Clamp diameter:38-55mm/1.5-2.2inches Package Contents: 1 * Square Hole Drill Bit Only the above package content,other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.