Lightweight secure fitting glasses. The half frame creates obstruction free peripheral vision. Panoramic view enables maximum eye protection. 100% protection against harmful ultraviolet rays. Lightweight and shatterproof polycarbonate lenses. Superb visibility in strong glare conditions. Wider lens coverage providing further protection to your eyes from wind, sand and flying objects. With flat arm profile making them perfect for wearing under caps or helmets. With a low and medium light interchangeable lenses that are lightwieght and shatterproof also. Ideal for Running, Cricket, Cycling, Motorsports, Skiing, Golf Outdoor pursuits or Leisure.Category 3 lenses, effective in strong light.Spare lenses that are included with these sunglasses are: Clear Cat 0, to block wind, sand and flying objects. Yellow Cat 1, can enhance light during winter or low light conditions. Contrast to use on green grass. and Orange Cat 2, for protection in medium light conditions.Blue - Blue frame, white inside with red features. Smoke mirror, orange, yellow and clear polycarbonate lenses.Black - Matt black frame with orange features. Smoke mirror, orange, yellow and clear polycarbonate lenses. It is very simple to change the lenses in your Interchangeables.Step 1. Stretch open the frame and release the inner corner of the lens.Step 2. Release the outer corner of the lens.Step 3. Insert the outer corner of the replacement lens.Step 4. Stretch open the frame and push in the inner corner of the lens.