CSUN 305W polycrystalline solar modules provide long-term reliable power at a reasonable price. Each module includes a 10 year materials and workmanship warranty, and CSun's exceptional 25 year linear output warranty ensures your solar modules provide no less than 97% of minimum guaranteed output power when you install them, and no less than 80.2% after 25 years (maximum allowable loss of 0.7% per year).