Dual power source flexibility - Solar energy during daylight or USB power for continuous ventilation. This two-option system delivers long-lasting cooling in any weather and maintains fresh airflow day and night without draining your car battery. General car compatibility and build - Fits most vehicle windows with adjustable solar panel positioning and secure self-strips (84*4 cm). - Compact 16*10*3.5 cm ABS construction installs easily and promotes optimal sunlight exposure for maximum energy efficiency. Heat reduction and visibility - Actively lowers cabin temperature by up to 15°F through efficient air circulation. - Reduces heat buildup and helps minimize windshield fogging for improved driving visibility. Air renewal system - Continuously refreshes the interior by expelling stale air, smoke and odors while drawing in fresh outdoor air. - Improves overall air quality for a healthier environment during daily commutes or extended travels. Use scenarios - Daily city commute on hot days: solar power handles daytime cooling, USB keeps ventilation running when needed, without stressing the car battery. - Long road trips or parking in sun: significant cooling and reduced fogging help maintain comfort and visibility. - Extended stops or camping: interior refreshes by removing odors and drawing in fresh air for a cleaner cabin.