Castelli Active Cooling Sleeveless Baselayer; - Made from Castelli's famous Prosecco fabric, which has had an 'Ice' element added to it for extra cooling effect. - Dispersing moisture over the whole body to speed up evaporation and wicking of sweat. Basically, this system keeps you cooler and drier whilst exerting effort. - The use of Energy-activated technology further aides moisture control. - The Active Cooling Sleeveless gives visual indication of where it is working. As you sweat, the fabric will lose its pattern - even squeezing it in the palm of your hand can activate the dynamic print. - The ultra-lightweight material also has a 50+ UPF protection applied to it keeping the sun's rays at bay. - In a clean looking white colour scheme and sleeveless cut, for an ultimate warm weather baselayer. Very light and available in a wide range of sizes.