When you want a tee that goes the distance this is a great choice. It works in harmony with your body to help keep your climate under control. ARGENTIUM® PRO technology reacts to the physiology of your body, becoming extra cooling and breathable when you heat up, and working to be more protective when you start to cool down. To keep you feeling fresh at the end of a tough challenge, it has fantastic wicking properties combined with lasting odour resistance, and for extra measure, mesh panels boost ventilation in key heat zones. Staying safe in the sun is easier thanks to the UPF protection of 30+ thats built into the main fabric . A fantastic choice for cool confidence in the mountains. 185g (Size M)