Size:6 Pack Double Stud w/ ‘O’ ring – 5,000 lb. capacity rating. This fitting fits all aluminum tracking similar to the track in the image above. Double stud refers to the number of ‘fingers’ that it captures when attached. The fittings’ steel base is zinc plated to inhibit corrosion. It is SPRING LOADED to permit simple attach and detach operation. To detach, simply pull up on the spring loaded mechanism and then slide forward or back and the fitting releases. To attach, rest the fitting in the load track, then push down on the base and push forward. The double stud fitting attaches to two sets of ‘fingers’ in the load track, thus giving you a more secure attachment than the single stud fitting. IT IS NOT recommended to pull at an angle greater than 45 degrees. As a rule of thumb you lose about half your rating at a 45 degree angle. * WLL The maximum load weight a tie-down should be subjected to during normal use. To assist in making the proper tie-down choice the Federal D.O.T. requires the W.L.L. to be 1/3 of the Rated Capacity.