Designed and extensively tested for dogs under 7kg giving your dog the most ergonomic and snug fit possible. The unique Ultra Buoyancy Foam is positioned strategically around the vest to keep your dog in a natural swimming position at all times, without hindering the natural movement of your dog. 50% more flotation material than standard dog life jackets, to ensure your dog keeps upright in water. The Micro DFD does not need to cover your dogs entire back length to be effective.