According to the manufacturer's specifications, a filter cartridge lasts about three to six months depending on the use and storage of the air cooler. Evasmart indicates with a red light when you should replace the filter cartridge. Poor water quality can further shorten the filter's lifespan. Please do not store the replacement cartridge for more than three years to prevent it from losing its evaporation capability. Follow the instructions in the user manual carefully when replacing. Compatibility: Evapolar Evasmart air conditioner. Lasts three to six months depending on storage, usage, and water quality. Can be stored for up to three years without loss of quality. Equipped with a microchip to monitor lifespan. When the cartridge's lifespan is nearing its end, the device lights up red.