Disposable swim diapers are not very efficient at containing accidents. If you are teaching your infant survival swimming skills required to safely enjoy the water at a swim school, ZOOCCHINI's Reusable, Waterproof Swim Diaper is a must. Make good choices and stay safe in the sun. UPF50+ clothing helps protect against sun, but sunscreen should be applied to any skin that is not covered by a sun protective garment (face, ears, hands, etc.) Age 6-12M: 15-22lbs | Waist 7.25"-10" extended Age 12-24M: 22-30lbs | Waist 8"-11" extended Age 24-36M: 30-36lbs | Waist 8.75"-12" extended Designed to be worn alone without need for a diaper. If using over a bathing suit or a diaper, please consider the next size up. Package Includes: Reusable Knit Swim Diaper 2-Pc Set Designed in the USA