Product Description Fastskin FSII Jammer. FASTSKIN This fabric surface mimics the rough shark denticles to reduce drag along key areas of the body. FLEXSKIN This smooth surface material allows greater flexibility and less drag. Just like the sharks skin, Fastskin and Flexskin were positioned to accommodate the changing flow conditions along the swimmers body to create the most advanced and lowest drag racing swimwear in the world to date FASTSKIN FSII. Available in Black, Navy and Silver in even sizes 24 through 36.