A larger version of the Flak Jacket, the Xlj also has interchangeable lens designs with unbeatable optical clarity. Flak Jacket Xlj sunglasses feature Oakley Hydrophobic, a permanent lens coating that prevents lens smudges and build up. Multiple High Definition Optics lens colors are available. The frames are made of lightweight O Matter for all-day comfort and pure Plutonite lens material filters out 100% of all Uv rays.