Adrenalin Mens Short Sleeve Rash Vest Highest quality Span-Flex Lycra for flexibility and protection. The Adrenalin rash vest range are of a superior quality. The span-flex lycra material is not only comfortable but has a UPF rating of 50+ which means it blocks out over 97% of the sun's harmful UV rays and is fade resistant, making this rashie last much longer. The rash shirt has also been cut with extra length in the back to prevent ride-up and has a turtle neck for extra sun & rash protection.