two glass mask ultra clear optical lenses advancedDo you want to enjoy the colourful splendour underwater twice over? If so, the VM 50 two lens mask is the right mask for you. The high quality ultra clear lenses of the VM 50 significantly improve your visibility underwater as they have a light transmission of up to 94%. Unlike conventional float glass lenses, which have a light transmission of just 86%, ultra clear lenses don't have the green tint of standard glass. Our next generation ultra clear