Single stud fitting is designed to be used with l-track (also sometimes called logistic track or airline track due to its popularity in the airline industry), to create a secure tie down point quickly. The large o-ring accepts a wide variety of hooks, snaps, and straps. Once installed, it can handle 4,000 lbs. Of pressure. The spring-loaded plunger-style mechanism is easy to use: place thumb inside the ring and push down on the stud while lifting the clip with your index and middle fingers. Insert the bottom disc into the desired round opening on the track. Slide the fitting in either direction so it's halfway between two of the tracks openings and let the clip fall on both sides of the fitting in the round slots on either side of the stud. To remove, simply lift the clip, slide to an opening and remove from the track.