Heavy-duty heavy-duty screw clamps designed for securing flexible, hard rubber, plastic-reinforced or steel tubing used inin vacuum and pressure installations. • made of aluzinc-coated carbon steel (W 1)• protected with anti-corrosion coating• GBS toggle closure with two pins• hexagonal screw head allowing the use of open-end, socket and adjustable wrenches• high-quality steel strip with a width of 18 mm• diameter: 21 - 23 mm• quantity: 4 pieces