Lexan Thermoclear 15 is an impact resistant, energy-saving, multi-wall polycarbonate glazing sheet. It features a proprietary surface treatment which provides resistance against degradation caused by UV radiation in sunlight. The entire Lexan Thermoclear sheet line carries a Fifteen Year Limited warranty agains discoloration, loss of light transmission and/or loss of strength due to weathering. Lexan thermoclear 15 offers a 15-year Manufacturer Warranty against yellowing as well as breakage caused by hail. The AmeriLux 5-Year extended Warranty increases total coverage to 20 Years. Note: Sheets are supplied with poly-masking on both sides. the side that is printed should be installed face out.