[Easy to Use & Replacement] The size of the humidifier cleaner fish is 2.3 x 1.8 inches. The opening diameter of the humidifier should be at least 1.8 inches. This humidifier tank Cleaner fish contains no harsh chemicals. [Purifies Water & Eliminates Mineral Build-up] Using humidifier tank cleaner fish can effectively reduce the accumulation of white matter caused by Mg²+ and CA²+ in hard water, and remove more than 90% of unpleasan odors. Keeping your tank clean as new provides you and your family with a cleaner, gentler mist output, while extending your humidifier's water absorption and effective lifespan. [Work Fit Most Humidifiers] Work with evaporative, ultrasonic,Warm & Cool Mist Humidifiers, Vaporizers, Steamers, and Fish tanks, and well for a humidifier wicking filter. Just put it in the slot and working. [Keep your Humidifier Clean] The humidifier cleaner fish has excellent cleaning performance, prolongs the life of the humidifier filter and keeps the water clean. The humidifier cleaner can prevent other odors by improving the water quality of the humidifier.