.We use them to carry car keys on our belts; we even rappel down cliffs on them. Everybody knows the quickest, safest way to attach something valuable to something else is to clip it on with a metal carabiner.That's the idea behind Courier Clip. It's got a tough silicone case for your iPod nano, with a detachable metal carabiner, ready to clip onto your belt, backpack, handlebars, hatband, tentpole, even your climbing rig.Courier Clip is the most secure way to carry your iPod nano. It can even keep track of your car keys for you.