Julbo's Ultimate Cover Sunglasses offer peak-performance visibility and versatility for mountaineering, alpine climbing, backcountry touring, or even training in lower altitudes. The nose cover and side shields are removable when we're out of the alpine sun's gaze, and the nose cover gives cover to cold wind as well as harmful UV rays. Even better, the REACTIV photochromic lens gives extra shade when we're on sunny summits, and less shade when we're trekking through shady trees, while the Spectron lens is lighter and offers shock resistance.