Cycling Glasses Photochromic Sunglasses Earphones & Headphones It's a perfect gift for

It's a perfect gift for your bohemian friends

It is more focused on the moisture wicking performance

No need for separate sharpening boards

Easy to use: No programing or pairing needed

Built-in 2000mAh lithium battery supports up to 2 hours of max brightness and 10 hours at minimum brightness

Cycling Glasses Photochromic Sunglasses Earphones & Headphones It's a perfect gift forDetails Photochromic lenses have UV400 function and will change color under direct sunlight. Discoloration occurs in about 1 minute in winter and about 40 seconds in summer. Speed depends on sunlight and UV intensity! (If the UV intensity and temperature are low, the color change rate will be slower.) The color change rate is related to the UV intensity and temperature.