The lenses of these glasses change between cat2 ... cat4, which means that glare protection is sufficient even in extreme conditions, when snow or water reflects sunlight from all directions. Cat4 is so dim that we can't recommend these glasses for use when driving or riding a motorcycle. - Lens: Polarizing and photochromatic, adjustable visible light transmission between 7% ... 40% - Basic lens color: brown - The inner surface of the lens has an anti-fog treatment - The lens changes its glare protection very fast as conditions change - Shaped Grip Tech pads on the temples - Air Flow ventilation - Flexible nose pad - Removable side guards - Size M frame: - Lens Height (mm) : 43 - Bridge Distance (mm) : 17 - Temple Length (mm) : 120 - Base : 6 - Lens Size (mm) : 54 Julbo has been making sunglasses for more than 135 years. By buying Julbo, you are investing in a quality product and can rest assured the glasses offer perfect UV protection.