Smith Optics Turbo Fan Series offers the best ventilation system ever seen on winter sports goggles! The vets at Smith Optics are ski goggles specialists, and the Smith Turbo Fan Goggles come loaded with the best feature that they can offer. This series of Smith Snow Goggles features a patented micro-electronic fan that draws fresh air into the goggle chamber through strategically placed vents, and exhausts moisture to prevent fogging. Turn the silent-running fan on when you get to the hill and in the low setting, the Smith Turbo Fan Ski Goggle system will run continuously all day long - up to 50 hours on a single AAA battery. The high setting can be used to quickly exhaust moisture from the ski goggles in extreme conditions. The Smith TurboFan Series of snowboard goggles is fully helmet-compatible and offers articulating goggle straps, Carbonic-X lenses with tapered lens technology, dual-layer Driwix face foam, and sealed thermal lens technology to prevent between-layer fogging. These Smith goggles have been to the top of Mount Everest and back - they can take on any slope!