SPEG UV-Pro Cycling Head Cooling Helmet Liner, SPF30 Offers moisture wicking, cooling and UV30+ protection for those with medium to short and zero head hair. Manufactured using a combination of CoolDry fabric and Spandex for flexibility The CoolDry fabric combines the comfort of cotton and the quick-dry performance of polyester fabric The tetra channel structure of the fiber makes CoolDry more breathable, which repels the moisture quicker and keeps the body drier and more comfortable