Innovative design for competitive swimmers.Worn by world class swimmers, the Fastskin LZR Racer X Openback Kneeskin features targeted compression to streamline the body while still allowing for excellent freedom of movement, making you feel your fastest. Support seams help promote better body positioning and increased muscular awareness, while Speedo’s laser-cut Ab activators panels in the suit’s liner increase water sensitivity and prompt you to align yourself correctly. This product has been fully approved by FINA.