Customize the look of your Flak Jacket XLJ eyewear and get the best optical performance for where you use it most. All replacement lenses feature the unbeatable clarity, impact resistance and 100% UV filtering of Oakley's HIGH DEFINITION OPTICS® (HDO®). Important Note: Replacement lenses may not be returned if they have been mounted or scratched. Asian Fit lenses cannot be installed in standard-size eyewear frames.