NEW Madewell Black Ribbed Square-Neck Bikini Top Medium New with tags. No known flaws. This item has been carefully inspected and is stored in a smoke-free home. Sustainable and swim-ready, our Madewell Second Wave collection comes in feel-good recycled ribbed fabric. Sporty and minimalist, this bikini top has a square neckline. Moderate support. 93% recycled polyamide/7% elastane. Do Well: made with recycled fibers that could have otherwise ended up in landfills. Machine wash.