Fit Guide Fits true to size, but a tad smaller than a T-shirt. Size up for a looser fit. Benefits UPF 50+ rating blocks harmful sun rays. Engineered stretch that won't bag out when wet. Breathable, antimicrobial armpit panels keep you feeling fresh. Quick dry fabric wicks moisture. Details 100% recycled polyester Machine wash cold. Hang dry. Imported The shirt we use for surfing, sailing, hiking and anything else under the sun. The Florence Sun Pro Short Sleeve UPF Shirt features a 50+ UPF rating, moisture-wicking fabric to keep you cool and a 4-way stretch knit construction that doesn’t bag out when you get in the water.