Description from the vendor website:

Ideal for when you're looking to keep your pup close or leash up two dogs, with our Double Track™ Coupler, the supple, reflective kernmantle rope and auto-locking carabiner create a secure connection. The tri-action, swiveling carabiner keeps walks twist and tangle-free, and the convenient accessory loop lets you carry all your canine essentials.

The strong rope core in the Knot-a-Long™ is made from repurposed remaining yarns, which helps reduce impacts from disposal, recycling, and material production.

Rope Length: 30 in (.76 m)
Rope Diameter: 11 mm

Carabiners not sold separately