Paws Aboard Life Jackets provide ultimate buoyancy and high visibility to keep pets safe on the water. These dog lifejackets are constructed of durable non-chafing materials to provide the highest levels of buoyancy and all-day comfort. XXS: up to 6 lbs. XS: 7-15 lbs. S: 15- 20 lbs. M: 20- 50 lbs.