This is not a complete set. The box was damaged during shipping. One of the mounting plates is missing. There are (4) d-rings but only (3) mounting plates.

D Rings Heavy Duty 1/2" Trailer Tie Down Anchor 4 Pack Black

Max 12000Lbs, Forged Steel, Anti-Rust, Bolt on D Ring, Truck Bed Hooks, Utility Accessories for Trailers, Trucks, Cargo.

CONVENIENTLY&QUICKLY- Install with Drilling, No Need for Welding. By threading a screw or bolt through the 1/4" diameter bolting hole on the mounting clip and securing to any wood or metal surface. The trailer d rings tie down is easy and convenient to use once installed. d rings for trailers provides an anchor ship for all cargo tie downs. [Note: The length of the bolt is 3.15"]

HEAVY-DUTY- 12000 lbs Strength. The D ring tie down anchor are made of heavy-duty steel for safety and durability. This trailer tie down ring is ideal for heavy duty applications acting as the foundation in tie down technique while moving cargo in your truck or trailer. The d rings heavy duty has a remarkable working load limit allowing it to accommodate tractors and other heavy freight.