Cold Sprayer Fish Tank Cleaning Water Filter Humidifier Cleaner Tool 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. Material:plastic Colour:Purple/Blue They look very cute floating around in the fish tank,humidifier. These are allowing the water to stay cleaner and less tank cleaning times. Work with evaporative,ultrasonic,Warm & Cool Mist Humidifiers,Fish tanks,and well for a humidifier wicking filter. 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. Package Contents: 1/10 x Humidifier cleaner Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.