AquaLung Outlaw Rash Guard Man AquaLung’s rash guard fabric is made from 80% polyester and 20% Spandex. The polyester helps keep colors fresh and bright All rash guards are SPF 50, offering the maximum protection against UV Athletic fit is adapted to diving and watersports; the back is longer than the front and has a loop stitched on the front to attach the string of the board short or a men’s swim suit A small collar protects the back of the neck from friction when snorkeling or diving in warm water and helps to hold in warmth when used as undersuit