QUALITY MATERIAL:T Slot Nuts are made from Steel for the resistance available,protect the T-Slot Nuts from rust. Tapped through for 3/8 inch-16 threads for use with , racks, tie downs, custom cleats and more.Hex Bolts are made from Steel.tie down anchors are made of quality steel and they are fully welded triangular rings, which make the bolts sturdy and work for a very long time. WIDELY USED:Mount extra cleats,tie downs,,bike racks and more! With a 3/8inch-16 fully tapped and threaded hole, the possibilities are endless as to what you can attach.The tie down anchors are heavy duty 1000 lb rings,for securing ratchet rope, cam buckle straps, bungees cords,they are perfect to add tie down points for a truck, trailer, SUV, boat to carry heavy loads, and let you far away from cargo swing and noise. EFFECTIVELY:These T-slot nuts are perfectly compatible with bed rails in both for and for , but also work with a of other pickup trucks with compatible bed rails.By threading a screw or bolt through the 13/32inch diameter bolting hole( (that's between 3/8inch and 7/16inch). T-slot nuts are tapped all the way through allowing for the bolt to pass all the way through,simple to use and convenient to connect aluminum profiles to other parts. Colour: Silver + Black Material: Steel Package Contents: 4 * T Slot Nuts 4 * Screws 3/8 inch-16 4 * Nut 4 * Gasket 4 * Tie Down Anchors Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.