Shift MagGeared for speed. The Shift MAG gives cyclists and runners every performance advantage possible, from the superlight frame down to the nose piece. The coolest feature is no doubt the interchangeable lens technology. Snap the magnet on the side for quick, fingerprint free lens changes. These Smith sunglasses come with one clear lens as well as a color enhancing ChromaPop lens. Flatter than most performance eyewear, the 5 base frames stay put with a two