About Perfect when combined with the Flexlite Cooling long john, this Flexlite Cooling Long-Sleeve Top is made from UPF 50 certified, smooth 4-way stretch fabric. Gussets under each arm with mesh ventilation and flatlock seams are added for breathability and comfort, whilst the actively cooling finish reduces your body temperature and wicks away moisture. With the high collar, this sailing top is excellent for high activity on warm water in hot sunny weather.