Ounce-for-ounce, the Main Core Goggles are the best value on the market and feature Fox'sVariable 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 on the dirt while being light on the wallet.