【High Efficiency Solar Panel】The solar panel is covered with monocrystalline silicon solar cells and adopts multi-layer cell technology to generate power from sunlight, achieving a higher conversion efficiency of up to 23% compared to conventional panels. It only takes a few hours to fully charge the battery fan. 【4 Speeds & Ultra Quiet】The solar fan features the latest brushless motor technology and high-performance ultra-thin fan blades, equipped with 4 wind speeds, providing ultra-strong airflow at the lowest noise level (