The large interior volume of the Knowledge Turbo Fan OTG accommodates a wide range of eyeglass sizes while also fueling the fog-fighting performance of our patented Turbo Fan technology. Combined with our proprietary 5X Anti-Fog inner lens, the Knowledge provides incredible anti-fog performance for eyeglass wearers. Goggle Features Large fit Two-speed, micro-electronic fan Carbonic-x lens with tlt optics 5x anti-fog inner lens Patented vaporator lens technology with porex filter Floating foam membrane eliminates eyeglass temple pressure Articulating strap positioning system Ultra-wide, silicone backed strap Quickfit strap adjustment system with clip buckle 2-layer driwix face foam Ods 2 & eyeglass compatible Helmet compatible Microfiber bag included Red Sensor Mirror Lens Light rose base lens tint with a multi-layer red mirror maximizes color definition & increases depth perception in varying levels of flat light conditions. Light transmission of 55% for low/medium light conditions Category S1-2