Madewell Second Wave Square-Neck Tank One-Piece Swimsuit in Mod Shapes. Sage green color. Size medium. Great preowned condition. Sustainable and swim-ready, our Madewell Second Wave collection comes in feel-good recycled fabric. A fresh take on a tank style in a mod geometric print, this square-neck one-piece has a low back and a flattering legs-for-days cut. Light support: shelf bra. Moderate seat coverage. UPF 50 sun protection. 82% recycled nylon/18% elastane. Do Well: recycled from preconsumer waste that would otherwise go to landfills.