Evapolar Evaporative Cartridge is the part of evaLIGHT Plus Air Cooler & Humidifier, which needs to be replaced every 3-6 month to keep evaLIGHT Plus’s cooling capacity. evaLIGHT Plus Air Cooler provides exceptional performance thanks to innovative evaporative material inside. The material is the compound of natural basalt fibers, which has huge evaporative surface and strong capillary effect, allowing evaLIGHT Plus to create the most energy efficient personal air cooler. The material filters out the dust from air, prevents mold and bacteria from growing inside while being eco-friendly and fully biodegradable.