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. Rubber nose pads and sleeves for maximum comfort. Tighter fitting medium cut lenses so you still have the coverage but allowing slight air flow. Superb visibility in strong glare conditions. 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. White - Pearl white frame with yellow features. Red platinum, orange, yellow and clear polycarbonate lenses.Grey - Metallic grey frame with orange features. Red platinum, 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.