Features: 1Woodworking clamps need to be used in conjunction with a perforated table top the hole diameter needs to be 20mm and the hole spacing is between 80mm150mm. 2The size of the first opening can be adjusted according to the thickness which is suitable for accommodating boards of different thicknesses. 3Suitable for all kinds of woodworking mechanical maintenance diy projects and all kinds of desk clamps and puzzles. 4Planing sawing drilling and grinding can be safely operated. The board can be combined horizontally or vertically making the operation more convenient and flexible. 5It is specially used to hold the plate firmly flexible and convenient and is a good helper for you to handle various operations of the plate. Specification: Item Type: Desktop ClampProduct Size: Approx. 260x65mm / 10.2x2.6inApplication: combined with a desktop with an aperture of 20mm it can easily clamp and fix the wood board for sawing grinding and drilling operations which is stable and convenient Package List: 2 x Desktop Clamp4 x Fastening Accessories2 x Limiting Accessories1 x Chinese and English Manual