The Arena Cobra Ultra Swipe Mirror Swim Goggle features Arena's anti-fog swipe technology. The Cobra family's existing anti-fog treatment is already one of the best. Now with Swipe technology Arena made it even better! With just a single swipe of the finger Swipe Anti-Fog can be reactivated extending the protection up to 10 times longer! When goggles become foggy gently swipe the inner lenses with your fingertip while the goggles are in the water and enjoy clear vision for longer.