Product Warranty and Features 20-year performance guarantee. 90% performance guarantee for the first 10 years, 80% power efficiency guarantee for 20 years All panels are resistant to 2400 pascal wind and 5400 pascal snow pressure. Anodized aluminum alloy frame Tempered 3.2 mm, 90 N/mm2 resistant, non-reflective, 92% transmittance quality windshield protection. Working Environmental Conditions; 0% to 85% relative humidity at 1500 meters altitude. Superior Solar Panel Performance Thanks to the -0% Watt and +0% Watt positive power tolerance, the power output of the modules you purchase is ensured at and above the label values, and the overall system efficiency is prevented from decreasing due to module incompatibility. Quality and Reliability ISO 9001:2008, ISO 14001:2004 and ISO 17025:2005 Testing for Harsh Environment (IEC 61701, DIN 50916:1958 T2) Guarantee 10-year product warranty 20-year performance warranty