The Ruffwear Knot-a-Leash(TM) is a rugged, climbing-inspired dog leash that uses strong, supple kernmantle rope and a secure locking carabiner. Reflective rope keeps dogs and humans visible in low-light conditions.Carabiners not sold separately. Small size: 5 ft long and 7mm ropeLarge Size: 5 ft long and 11mm rope