Obermeyer’s CZV™- Control Zone Ventilation builds upon several of our other technologies such as waterproof breathable fabrics and weatherproof construction to bring about another level of breathability and comfort to your outdoor experience. Outdoor activities often require an elevated amount of cardio generation in cold temperatures. Thermal regulation through venting is required when the amount of heat generated by the body exceeds the ability of the fabric's breathability to diffuse body heat and moisture vapor. Our venting is designed to allow heat to escape, fresh air in to assist evaporation and an internal mesh insert to keep out the elements when open. Pit Zips, chest vents, and thigh venting are integrated into most of our garments – check your preferred style's features for CZV™. With all these features we realize just how important it is to keep you comfortable, dry and warm by moving air around your body to evacuate unwanted moisture and heat.