Combine innovative lenses with highly versatile interchangeability, and you'll begin to understand what it's like to run or cycle with Tifosi Optics' Escalate H. S. Photochromic Sunglasses. Each pair comes with a half frame with two interchangeable lenses and two frameless Shield frames with fixed lenses. The Shield frames feel 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.