Disposable type, no citric acid cleaning required Set of 2 [Model Number] H060524 is a disposable antibacterial humidification filter for hybrid humidifiers. The differences from other model numbers (H060518, H060511, H060509, etc.) are mainly in the compatible models and the size/performance of the filter (antibacterial properties, water absorption, breathability, etc.). H060524 is a new type specifically designed for "easy replacement," eliminating the need for citric acid cleaning. It should be replaced approximately once per season, allowing for easy maintenance of cleanliness. In other words, H060524 is a new generation of humidification filter that emphasizes ease of maintenance. 60h03816