ROK Couplers are designed to walk two dogs with a single lead. The couplers are made with strong natural rubber and nylon webbing, which like the ROK leads provide progressive tension. A choice of 3 sizes are available, Small, Medium and Large. Each coupler has 1 swivel hook which attaches to your lead and 2 swivel G clips which attach to your dogs collar. The swivel hooks enables full 360 degree movement which will not tangle you dogs up whilst walking.