Sure, you usually use a leash, but if you've ever seen a ski with a busted leash going mach 10 down a groomer before flying off a mogul into the great beyond, you might consider using the 22 Designs Outlaw X Brakes. Or imagine you're in the backcountry and that mogul is a cliff. If nothing else, the trek down to you ski should be enough to consider adding a little safety net to your telemark bindings.