The Smith Men's I/o Mag Asian Fit Snow Goggles were designed for optimized performance and perfected fit! They use the Smith MAG™lens change system for amazing ease of changing out lenses. Two locking mechanisms give you lens security, AirEvac™ventilation adds fog-free integration with Smith helmets. The frame is designed for contoured face fit. All this technology is designed around one of Smiths largest spherical lenses, providing a maximized field of view and 5X™anti-fog technology. The I/O MAG™was designed through a process of reducing elements to only the most essential, so theres nothing getting in the way of a great day on the mountain.