PENN-PLAX presents the Small World Filter. This filter is specifically designed for aquariums and tanks up to 5 gallons. In addition to our Small World, New World, and Betta World habitats, this filter is compatible with other tanks in the market. It fits all shapes and sizes, and also mounts securely to glass, acrylic, and plastic surfaces. Furthermore, it's safe for both Freshwater and Saltwater setups. Carbon & Zeolite Mixture: Supercharged with scientifically formulated Carbon and Zeolite Crystals, the media cartridge in this kit absorbs ammonia, nitrites, nitrates, and phosphates in a fast and timely manner, along with removing harmful chemicals and toxins, clearing up discolorations, and reducing foul odors from your aquarium, tank, or habitat. Bio Sponge: In addition to the Carbon and Zeolite Crystals, the included media cartridge also contains a Bio Sponge for physical filtration of larger particulate matter, and biological filtration that optimizes the colonization of anaerobic bacteria. Cleaning & Maintenance: Before placing into your aquarium, tank, or habitat, please briefly rinse the filtration unit with warm water in order to remove Carbon or Zeolite dust. If not done before installation, the water could initially become dark or cloudy. For best results, the disposable media cartridge should be replaced every 2 – 4 weeks, ensuring a crystal clear and healthy environment for your fish. Please Note: The Small World Filter (SWF1), does not come with Air Tubing or an Air Pump, which are Sold Separately. This Aquarium Filter comes with a Mounting Bracket w/ Suction Cups for strong and secure placement, a Disposable Media Cartridge, and a Connector that allows easy connection to standard size air tubing. Measurements: Filter Mounting Bracket with Connector (1.5" x 1.25" x 5"), and Filter Media Cartridge (1.3" x 1.1" x 4.1").