The Scott Prospect Goggle Double Works Lens are packed with features...Specifications Include:100% UV protection - all Scott lenses are optically engineered to screen out 100% of harmful UVA/UVB raysImpact resistance - in order to ensure that riders are safe from the impact of pebbles and flying debris all Scott lenses not only meet, but exceed the required impact resistance standards required for MX lensesNew 4-pin works lenses - with this system the tear offs will always remain tight to the lens and provide the rider a better visionFor light sensitive versions of the lens - Scott light sensitive lenses engage photo-chromic technology and adapt automatically to sunlight intensity. These lenses react to light changes and within seconds the lens will darken when the brightness gets stronger or lighten then the sunlight gets weaker