Sometimes itís very convenient--and even safer--to have a hook that swivels smoothly and freely under load. It makes positioning and turning the load much easier, and helps keep associated rigging components from facing undo stress due to load binding. These hooks are extremely popular because they offer a great ball bearing design that allows the hook to rotate a full 360º while under load. They also feature a popular self-closing design that means the hook latch (made from heavy-duty alloy steel) closes instantly once a load is applied to the hook. The latch cannot open while the hook is under load, yet releases easily once the load is released. This hook also utilizes Gunnebo's "Grip Latch" that locks into the point of the hook for quick and easy visual confirmation that hook is fully closed and engaged. Each hook is proof-tested and certified with a 4:1 safety factor.