Description: Durable MaterialThe square hole drill fixed bracket is made of high quality stainless steel material, wear resistant, high hardness, sturdy and durable. FitmentThe square hole drill bit adapter is fit for table drill and hand drill clamp with a diameter between 38mm to 55mm/1.5 to 2.2inch. Bench Drill Mortise AccessoriesThe square hole drill bit adapter converter is easy to install and remove, you can quickly install or remove it yourself, fast and convenient. PreciseMortising attachment for drill press, precise design, ensuring accurate and smooth drilling. Wide ApplicationThe square hole drill bit adapter bracket is perfect for woodworking, furniture making, and other industries. Specification: Material: Stainless Steel Size Chart: 10cmx1.9cmx5.5cm/3.94inchx0.75inchx2.17inch Package Includes: Optional: Single: 1 Square Hole Drill Bit Adapter With Screws: 1 Square Hole Drill Bit Adapter, 4 Screws Set: 1 Square Hole Drill Bit Adapter, 4 Screws, 1 Nut Note: Please allow slightly errors due to manual measurement and different monitors.