FOX MAIN Interfere Smoke Adult MX GoggleThe best value in motocross and mountain bike goggles Ounce for ounce, the Main Interfere Smoke Goggles 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 lens functionality, they are a heavy hitter and light on the wallet.