Sustainable. Found: a bulk-free swim diaper that *actually* works. Says customer Kelly: “I won't buy swim diapers anywhere else in future summers! The material is so lightweight, I couldn't believe how absorbent it was without having the bulky padding I'm used to from our other reusable swim diapers.” Fabric & Fit Fabric: 80% recycled nylon/20% spandex, with UPF 50 protection; lining is 100% water-resistant recycled polyester that contains waste without absorbing or swelling. Feel: Lightweight, smooth, and stretchy. Fit: Comfortable, snug fit around the waist and legs. Can be worn alone, unless your pool requires a double layer. (Swim diapers of any kind are designed to contain waste, not liquids.)