Excellent material: D-ring made of strong high-strength iron, lightweight and easy to carry, will not corrode or rust, with a black protective layer to ensure they are used for a long time. Easy to install: The tie-down ring is suitable for any surface or floor. It is recommended to install a 1/4" diameter bolt to fit the 9/32" hole in the mounting clip. Multifunctional anchor hook: Due to their robustness, these D-ring anchors have various uses. The V-ring on the anchor provides a comfortable anchor point for ropes, bungee cords, ties or straps. They can be used as a wall hook in organized garages, warehouses and workshops. Wide range of applications: D-ring tie-downs are perfect for securing straps to crates or for trailers, tarps and anchor points for ropes. Package Included: 40 x D-Ring Fasteners. Note: Package no nuts or bolts included. Function Description: The shape of the D-Ring Tie Downs is suitable for securing anchors for kayaks, trucks, off-road vehicles and other bodybuilding equipment. It is also suitable for indoor and outdoor use, for sneakers, hammocks, awnings, refrigerators and similar appliances, moving boxes, camping equipment etc. Specifications: Material: Iron Type: Tie Down Ring Color: Black Size: D-Ring Thickness: 3mm The diameter of the installation hole: 4.5mm Package Includes: 40 * D-Ring Tie Downs Note: 1.Please allow 0.5-1cm deviation by manual measurement. 2.Please check the measurement chart carefully before making a payment. 3. The D-Ring should be used as a cargo tie-down anchor only and not intended for overhead lifting.