Work Fit Most Humidifiers - Work with evaporative,ultrasonic,LEVOIT LV600HH,Warm Cool Mist Humidifiers,Fish tanks,and well for a humidifier wicking filter. Attention - Humidifier opening should be at least 1.8 inch diameter. Please check the opening of your humidifier whether it is large enough to fit these humidifier cleaner fish. Cute Cleaner Fish - They look very cute floating around in the fish tank,humidifier. These are allowing the water to stay cleaner and less tank cleaning times. Excellent Performance - Humidifier Tank cleaner fish have excellent performance,it can extend humidifier wicking filter life and keep the water clean.Improve the water quality of humidifier performance.Prevent objectionable odors tastes. Value Pack - Contains 10 pack.We are committed to offer 100% high quality customer service and High-quality product, If you have any questions about the humidifier cleaner fish,please contact us and we will solve the issue ASAP.