With interchangeable frames and photochromic lenses, the Tifosi Optics Escalate F. H. Sunglasses might be the most innovative shades for cyclists and runners. Each pair comes with a full frame, two interchangeable lenses, a half frame, and two more interchangeable lenses. The half frame feels best during high endurance workouts, while the full frame has a more casual look for life off the bike. A simple clip lets you interchange each frame in seconds, and the padded temples and nose pads adjust for a personalized fit. A photochromic Fototec treatment helps each lens adjust automatically to the ambient light around you. Tifosi Optics coated the scratch resistant lenses with a hydrophilic coating to repel water, oil, and dirt. Proposition 65 Warning for California Consumers: This product contains chemicals known to the State of California to cause cancer andor birth defects or other reproductive harm.