This is a high-performance dog flotation device for boating, water sport adventures and activities with dogs. Designed to protect your dog while allowing them to enjoy the water and provides an easy method of retrieving your dog if an emergency arises. A note about sizing: all pups are unique and special, especially yours! Sizing guidelines may differ dog to dog. Please choose your size after taking every measurement listed on the chart. Make sure to take any other unique traits (large shoulders, long torso, etc.) into consideration.