The Chlorine Resistant Active Back Plus Size Krinkle Swimsuit by Penbrooke? features the Penbrooke? Krinkle, engineered to last up to three times longer in chlorinated water than the average swimsuit. The 100-percent Polyester fabric allows for stretch and shape resistance. It helps comfortably support the bust area with its soft-molded cup shelf bra and active back design. It also creates a flattering silhouette with its tummy control panel that slims the torso area.