B-20.3 polycarbonate lenses give a clear, sharp view. They're three times lighter and 20 times more impact resistant than glass lenses. And they block harmful UV Rays too.Carbo Glas coating reduces scratching on both sides of the lens. Piranha comfortably fits medium-sized faces. And its frame is also made from B88 nylon. So it's both lightweight and durable.Pinless hinges join the frame front to the arms. With no weak mechanisms in the way, they add further durability. These sunglasses won't slip either. Because Thermogrip nose pads and temple tips soak up perspiration. Holding Piranha in place.