Check the listing for details. Hikari Aquarium Solutions Bacto-Surge Foam Mini Bio Sponge Filter Kit. Condition: New. Listed at 9.29 USD. Auction is for ( 1 ) : Hikari Aquarium Solutions Bacto-Surge Foam Filter - Mini Mini - 3 1/4" x 2 1/2 " x 2 5/8" high Aquariums up to 10 gallons *High-quality aquarium sponge filter for efficient biological filtration *Supports large bacterial populations to break down aquarium waste *Dense, high-quality foam ensure reliable longer lasting aquarium use The difference is in the quality of the foam sponge. Hikari Aquarium Solutions Bacto-Surge Foam Filter employs the highest-quality foam sponge they could source to provide outstanding mechanical and biological filtration. Extreme foam density allows for greater surface area per square inch to support significant levels of beneficial bacteria. In addition, the unique air dispersion design maximizes uplift to pull aquarium water through the foam at a higher rate resulting in optimal conditions for beneficial bacteria AND thorough aquarium filtration. Hikari Aquarium Solutions Bacto-Surge Foam Filter features locking internal connectors to prevent separation during operation and a heavy base to reduce chances of the sponge filter from floating. Ideal mechanical and biological filter for: Nano tanks Smaller freshwater aquariums Breeding tanks Fry holding tanks Quarantine tanks Use with slow moving fish like Discus Polishing of marine aquariums Please feel free to contact me for International and combined auction shipping rates or with any questions or concerns that you may have about my products. Thank you !