Full speed ahead. The Smith Shift XL MAG sunglasses are an oversized shield made from TR90 nylon for maximum coverage and performance on trail or biking adventures. Their wide-shield coverage maintains full vision at high speeds, while the ChromaPop technology enhances contrast and natural colors. Smith MAG interchangeable lenses use a magnetic clip for quick, fingerprint-free lens changes. Combined with a lightweight frame, non-slip nose pads and auto-lock hinges, they stay put through long, hot climbs, fast descents, and extended trail time.