Aquapapa Bio Sponge Filter Air Pump Driven Up to 20 Gal Breeding Fry Betta Shrimp Fish Tank Aquarium (Ship from CA USA) (Small 4-Pack)
Brand: Aquacity

Sponge filters are great for any size aquariums which provide both mechanical and biological filtration.

Bio Sponge filter is good for aquarium and provides both mechanical and biological filtration. The air infusion chamber produces numerous minute bubbles which promote gas exchange and increase dissolved oxygen level in tank water.
It's easy to set up. Just connect the unit with an air pump thru airline tubing.
These sponge filters do not trap fish fry and are safe for small size fish like dwarf cichlid, guppy, killifish, etc. They are useful for as breeding filter or as secondary filter. Or they can be used as pre-filtration unit by fitting to an external or a top filter.
Filter Dimensions: 3.0"D x 6.5"H - Recommended tank size up to 20 Gal.
Package includes: 4 pcs of sponge filters.