Built for the road, track, trail or sidewalk, the super-lightweight Stunt Runner™ keeps you and your dog in sync and your hands free. The extension is adjustable and when longest can create space for running with your dog single file on trails or up and down hills. Shorten it up for close, side-by-side urban running. We kept it simple, light and easy to adjust on the move The D-ring on the waist belt can be moved to specific position to keep your dog in the sweet spot without tugging on the waist belt Flex in the bungee section absorbs variances in stride, speed and direction Length adjustment allows dogs to run ahead, out wide or behind without creating a drag or drop on the leash when running in close and accommodates taller or smaller dogs Static portion provides a grab-handle