Functional Glasses, DUCO is No.1-Slogan Duco focus on a wide variety of functional glasses from night vision 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. 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 longer than 5-3/8inch, shorter than 5-1/2inches;height is less than 1-5/8inches, please buy it. 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.