JPeeThese also swivel. I use mine mostly for backpacks. Imagine clipping it on your backpack then being able to fasten the hook to branches, rocks, ledges, tailgates...anywhere the hook can grip. The swivel feature allows you to turn the backpack to access different pockets and zippers. It's not a necessary piece of gear, but I have several of these and they never leave my packs. Too handy. Photos in action: