Fastskin and Fastskin II, or FSII, are brands of high-technology fabric| swimsuits made by Australian swimming product manufacturer Speedo. The fabric is said to mimic the skin texture of sharks to provide increased speed in the water. FSII - the latest version of Fastskin technology - was released in 2004. Fastskins are made of 74% polyester and 26% lycra/spandex. FsII's on the other hand are 81% nylon and 19% lycra/spandex. The fastskin fsII reduces drag over the body by mimicing the denticles of a shark. The material is rougher in some places than others depending on the amount of drag that is usually experienced in that area. The fsII also features a turbulence management system (tms) which consist of a series of silicone dots on the chest. The fsII also uses two types of materials-fastskin and flexskin. The added flexskin in the suit contracts the muscles better, giving the muscles a spring effect to help you go faster.