Hang Ten Bright Rash Guard UPF 50+ 4 way stretch fabric (88% polyester 12% Elastane) UPF 50+ protection. A great T- shirt for any sport like Golf or snowboarding; or any gathering children’s games or day at the beach outdoors. Likes cold water. UPF stands for ​​Ultraviolet Protection Factor and is a scale to measure how much UV radiation passes through fabric to reach your skin when exposed to the sun’s rays