The Edge EyeWear SK-XL111 Kazbek Xl Safety Sunglasses - Black Frame With Clear Lens. Designed to absorb high impacts and look stylish while on the job or at play these safety glasses created by Edge Safety Eyewear were subjected to the toughest safety tests to insure your eyes are kept from harm and damage. Edge Eyewear knows that tough tests create tough glasses and because they are committed to maximizing eye safety they don't manufacture anything less than the best. Each frame consists of a TR90/Nylon compound that is both flexible and durable. The tip, temple, and nose piece all feature TPR Technology which is a material that reacts to heat and moisture to help keep your glasses in place by "gripping" more securely at each of those locations. The Edge EyeWear SK-XL111 Kazbek Xl Safety Sunglasses - Black Frame With Clear Lens also feature fog resistant and scratch resistant lenses that are uniquely tapered to eliminate refraction (warped or skewed vision). Edge Eyewear also understands the unique situations, people, and work environments that would constitute different features for different circumstances. Prescription or Welding Lenses as well as Ladies style and Gasketed Frames are just a few of the options available for your everyday and special occasion safety glasses needs.