The Iso-Chill material helps dissipate body heat and feels pleasantly cool. Mesh panel on the back for maximum breathability. The construction with 4-Way Stretch technology allows the material to be elastic in all directions. The material wicks away sweat perfectly and dries very quickly. This way you stay fresh even after a greater sporting performance. The back slit can be worn open or closed for better coverage and a slimmer feel. Reflective details for better visibility in low light conditions.