Smith's AirEvac system generates maximum airflow and via air channels built into the helmet. The innovative, all-weather Holt helmet, from active sports gear maker Smith Optics, can be customized with the included convertible pad kit to keep your lid warm on the winter slopes, and cool in the summer skate park. Temperature and moisture management, in both helmet and goggles, is the single most important factor in enjoying a day of riding, and Smith Optic's Dual Regulator ventilation system independently controls both front and rear sections of venting. By exhausting heat through the rear vents while maintaining a sealed front end, your body is able to effectively cool down when needed, but avoid the dreaded ice cream headache caused by cold air blasting against your forehead. Additionally, Smith's AirEvac system generates maximum airflow and removes warm, fog-causing air via air channels built into the helmet, keeping your head dry and your goggles clear. The system is especially effective when pairing a.