Functional Glasses, DUCO is No.1-Slogan Duco focus on a wide variety of functional glasses from night vision glasses,prescription glasses, sports cycling glasses,anti blue ray radiation computer glasses to UV400 protection polarized sunglasses. We endeavor to provide quality products at prices which provide value to our customers. Duco fit-over sunglasses are designed to wrap around your face blocking the sun from the side as well as perfect for anyone who wants the benefits of sun protection while wearing their prescription glasses. They're lightweight and easy to slip on over your prescription glasses. They also provide premium protection against the sun's harmful rays. It is 100% UV protection. Highly useful for sports, driving, and fishing by helping the participant in these activities to see more clearly. How to measure your prescription frames for DUCO sunglasses: 1- Measure the widest part of your prescription frames left to right, this is the "width". Next measure the height of the lens with frame included. 2- Choose the DUCO frame (below) that is slightly larger in width and height than your frame measurements. If your frame width is less than 5-3/8inches,height is less than 1-5/8inches, please buy common size. If your frame width is longer than 5-3/8inch, shorter than 5-1/2inches;height is less than 1-5/8inches, please buy plus size. If your frame width is longer than 5-1/2inches,OR height is larger than 1-5/8inches,please DON'T buy it. Package Glasses X1, glasses case X1, glasses cloth X1,glasses bag X1. More Choice Visit www.amazon.com/shops/ducoglasses for more information on DUCO glasses and extensive line of products.