The Ruffwear Trail Runner Dog Leash is a stretch dog leash for running, with a ruched elastic section at the dog end that softens sudden lunges and stops. The leash stretches to nearly 6 feet while the handle end stays fixed, and a swiveling, lockable aluminum clip secures the connection. What Our Gearhead(R) Experts Are Saying:"Mid-run, when my dog slows to sniff or surges ahead, the leash lengthens gradually instead of snapping tight. My stride stays even, and the pace stays smooth for both of us."