Due to differences in shooting lighting and display on the monitor, there may be slight color differences in the items. Please refer to the actual product received. Please do not maliciously refund&dispute The video has a simulated ultraviolet irradiation effect There is a comparison between video and shooting, and the actual effect captured by the phone photochromic protective cover can automatically adapt to light conditions by clicking the release button. It will darken when exposed to sunlight and brighten when exposed to low light. After exposure to the sun, sunglasses become more handsome! The working principle of color changing lenses is that when exposed to ultraviolet light, the color changing coating on the lens gradually darkens. The speed of color changing is directly related to the depth and the amount of ultraviolet light encountered. can reduce 80% %Light transmission, reduced by 30% before color change Helmets that can change color to 50-80% less light in strong sunlight for up to 30-40 seconds In the absence of sunlight, the color of the lens gradually becomes lighter, and it takes about 30 seconds to reduce the light transmission from 80% to 50% It is necessary to achieve 30% light transmission before color change, and a completely 0UV environment is required, such as at night. case for AGV K1 K5 K5S K5-S K3SV K3-SV helmets Not suitable k3 k4 helmets