Canada's Prime Minister Carney Meets with Trump Amid Strained Relations MTB Goggles Fox Main White. MTB Goggles Fox Main White The best value in riding goggles for mountain biking Designed specifically for mountain bikers, the MTB Main Goggles are designed to be worn with both full face and 3 4 shell helmets. Ounce for ounce, they are the best value on the market, and feature our Variable Lens System (VLS). VLS makes your goggles compatible with both standard lenses (stock) and injection molded lenses (sold separately) within the same frame. With an expansive viewport, triple layer foam, and tear off functionality, they are a heavy hitter and light on the wallet. Specifications MTB specific eyewear solution, designed to be worn with traditional full face and 3 4 shell helmets All new design offers best in class viewport for unparalleled vision Variable Lens System (VLS) design allows the transfer of standard and injection molded lenses in the same frame Triple layer face foam with fleece liner Lexan lens offers UV protection Strap mounted third tear off post Non slip silicone strap Microfiber goggle bag included Clear Lexan lens