Zayn draws from the aviation glasses of the early 1900s, its round metal front finished with a perforated side shield at each temple. Product Details Frame: Metal Lenses: CR-39 UV-400 protection blocks 100% of harmful UVA and UVB rays. Non-polarized, mirrored. Hardware: Perforated side shields, adjustable nose pads, acetate temple tips Size & Fitting Size: 50-20 Medium Temple length: 145mm Face Coverage: Standard. A medium lens front for those who prefer to cover an average portion of the face. Bridge: Adjustable Fit