Oakley blends style, comfort and practicality to produce an ultra-lightweight pair of shades with the SI Fuel Cell Tonal Flag model. The ergonomic, hi-modulus O-Matter frame is built to sit securely on the ears and the stems are comfortable enough to wear for long periods of time. Patented Plutonite lenses designed with High Definition Optics maximize clarity and protect eyes from harmful UVA, UVB, UVC and blue light up to 400 nanometers. The frame is stress-resistant and holds lenses in optical alignment, while eliminating pressure points behind the ear. The three-point fit ensures that the glasses only make contact at the bridge of the nose and the sides of the head for a comfortable, secure fit. This model features high-velocity and high-mass impact protection for maximum durability, and the tonal logo is an added tactical bonus for covert use.