The Mars has all the essential features to keep you enjoying your time in the mountains. The classic shape is designed to fit snuggly on small to medium size faces.Lens: VermillionVLT: 16% (CAT 3)Size: Small/MediumLens Shape: CylindricalLensVermillion – With a 15.5% VLT this lens is suited for bright through to medium light conditions.Visual Light Transmission (VLT) refers to the amount of light that penetrates a lens. A low percentage means less light passes through and a higher percentage lets an increased amount of light through. A lens with a lower VLT rating is better for bright conditions, where as one with a higher VLT is more suited for overcast and snowy days.