Fastskin® FSII is the most advanced and lowest drag racing swimwear in the world to date! The Fastskin® fabric mimics the rough shark denticles to reduce drag in key areas of the body. The fabric compresses the body to stop skin vibration and muscle oscillation to save energy and reduce drag. See FSII Info Center below for complete details. Fabric: 81% Nylon/19% Lycra® spandex. Import.