Specially engineered for youth faces, Flak® XS features the same innovations that athletes have grown to expect from the Flak® family. The lightweight O Matter™ design is offered in a range of colorways and Prizm™ lenses, and comes equipped with the sure grip of Unobtainium® nosepads and earsocks - making the style perfect for kids on the go.PRIZM™ LENSES:- Prizm™ is a revolution in lens optics built on decades of color science research. Prizm™ lenses provide unprecedented control of light transmission resulting in colors precisely tuned to maximize contrast and enhance visibility.Features: - Lightweight O Matter™ frame material with ellipse metal icon accents- Unobtainium™ earsocks and nosepads for increased comfort and performance- Polarized and Iridium™ lens options available Interchangeable lens system- Available with Oakley Authentic Prescription LensesSpecifications:Prizm Ruby PRIZM RUBY:- Light Transmission: 11%- Light Conditions: Bright Light- Contrast: Increased- Fit: Standard