SuperFlow features a large anatomic central relief area which allows rider to sit comfortably and pedal efficiently Fibratek: Selle Italia's latest cover material offering supreme durability and comfort Carbon Rails For more information on idmatch visit http://www.selleitalia.com/en/idmatchsystem/ L3: “Wide” intertrochanteric distance and high pelvic rotation (Flow and SuperFlow saddles) S3: “Narrow” intertrochanteric distance and high pelvic rotation (Flow and SuperFlow saddles)