otected and babies have a reusable swim diaper that fits comfortably while enjoying time in the water. Excellent Protection from the Sun and the Cold. The plush material is comfy for the bottom and the legs and waist sides are super stretchy. Provides UV 50+ UPF Protection from sun's dangerous UVA and UVB rays. Cressi even has a helpful size chart to choose the right size.Perfect for Swim Lessons. Nothing ruins learning to swim like having an accident while in the pool or poolside. The diaper's elastic waist and leg bands and waistband-drawstring provide a snug and secure fit without the discomfort of a diaper that is too small. This stops anything from leaking out of the diaper in case of an accident. This prevents embarrassment from the child as well as a lengthy cleanup from pool staff.