The Dragon DX snow goggles have a medium to large fit and designed and constructed to be compatible with a helmet. The frame will stay flexible in even the coldest conditions and the dual layer face foam and micro-fleece lining offer superior comfort and fit. Dragon's Super Anti Fog technology utilizes the same anti-fog chemicals used by NASA for spacecraft windshields and space helmet visors. the result is the strongest anti-fog known to man, lasting twice as long before fogging when compared to competitors.