Fine Sponge Filtration: The sponge filters provide mechanical and bio filtration and traps debris or waste without sucking up your fish, keeping a crystal clear water tank. | Mini Sponge Filter: 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 sponge 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 aquarium sponge filter 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.