Photochromic sunglass made for those who work or play mostly outdoors. Lenses react automatically to the sunlight. On overcast days lenses are medium to light. On sunny days they darken to a comfortable sunglass tint and when you go inside, they lighten up. Since they darken and lighten in response to the amount of sunlight you can wear them from dawn to dusk and never have to take them off. Optical quality lenses have 100 percent UV protection. Height 40mm hinge to hinge 130mm length 138mm. Chrome frame.