It's no fun skiing when you can't see what's ahead of you - so Atomic's FOUR Q HD goggles feature HD and Fusion Double Lens(FDL) technologies for crystal clarity on any skiing day. HD uses crystals in the lens to create insane contrast. FDL is a revolutionary double lens laminated together meaning no reflections, 8x more fog resistance than standards and an epic field of vision. Q stands for the Quick Click Lens system wo you can swap lenses in seconds. Included is a spare HD lens for better visibility in poor weather.