I am selling these items because I replaced my main unit due to a malfunction and no longer need them. The listing says there are three boxes, but I used one, so I am selling two boxes. Antibacterial humidifier filter specifically for SHIZUKU - Product Name: Humidifier filter for SHIZUKU - Material: Antibacterial material - Features: For ultrasonic aroma humidifiers - Compatible models: See images Thank you for looking. SHIZUKU, Shizuku, humidifier, cartridge