Fine Sponge Filtration: The 3 filters provide mechanical and biological filtration and traps debris or waste without sucking up your fish, keeping a crystal clear water tank. Mini Size: They measure 2″ D x 4.8″ H. Fit for 5 – 10 gallon small tank. Suitable for the breeding and feeding of various ornamental fish, shrimp or fish fry. Easy to Clean: Each filter can be easily detached for cleaning the dirt. Rinse it every 2 – 4 weeks with aquarium water ONLY. Avoid washing it in tap water! Quiet Aeration: Air powered and causing no disturbance to your daily life. Press the sponge into the tank to fully absorb tank water to make it sink to the bottom. Air Pump Not Included: You need an extra air pump to run each filter, which processes external air to promote oxygen circulation, providing a healthier tank environment. Easy to be cleaned,Up to 10 gallon tank