Keeper® Articulated E-Track fitting has a 2 in O-ring Anchor giving you ample room for a variety of hook sizes. These fittings are to be used with standard E-Track that you have mounted on your trailers, vans or in the shop. It is always handy to have a good supply of fittings with you to cover any cargo control situation you may run into. When not in use, simply remove and store in your tool box so they are always readily available.