Material: Aluminum Alloy ; Approx. 20mm / 0.79in ; Package List: 2pc . This table hole stop is perfect for 20mm (0.79 inch) hole, ensuring tight clamping without the need to shift out or use a knob to secure the clamp, fast and convenient. The woodworking hole table stop is made of excellent aluminum alloy with anodized finish, has high strength, and long service life. This aluminum alloy table stop can provide a firm clamping force in the rail, applying clamping pressure to any position along the T shaped slot or T shaped rail that is installed flush. his kit includes 2 pieces aluminum alloy table stops for easy use and replacement. With fine processing, these table stops have non slip finish, making them convenient and practical., Manufacturer: BUYTUS LLC