Strong and Durable: Tie-down hooks are made of high-strength steel, which is durable and has a long service life. Anti-corrosion and Anti-rust: Perfect for outdoor use. These bolt-on D-rings are finished with a premium black protective coating to prevent corrosion and rust, making our trailer hitches ready for the elements. Size: D-ring: 40x36x5mm (LxWxT), aperture: 5mm. One mounting hole is easier to install and looks cleaner. The wide triangular loop design makes it easy to insert various straps and hooks. Easy to Install: Simply insert screws or bolts into the 18mm diameter bolt holes on the mounting bracket and attach them to any wood or metal surface. Wide Application: Cargo tie-down rings add a convenient anchor point for securing ratchet ropes, cam buckles, bungee cords, or belts, ideal for cargo management on trailers, trucks, pickup trucks, flatbed trailers, utility trucks, pickup trucks, RVs, boats, kayaks, motorcycles, ATVs, minivans, SUVs, tailgates, flatbeds, warehouses, and garages. Our Service: We are committed to providing you with satisfactory service. If you have any questions, you can contact us at any time. We will reply to you within 24 hours and do our best to solve the problem for you.