Aquarium Filter Air pump Sponge Biochemical Oxygen Pump for Mini Fish Tank Supplies(XY-2881) Features: 1. Made of eco-friendly sponge and non-toxic plastic, safe and harmless to all fish.  2. Good filtering effect, can adsorb harmful substances and increase oxygen.  3. Adopted biochemical filtration, more effectively to filter impurities in the water and stablize the quality of fish tank.  4. Come with two fixed suction cups, faster fixing to prevent falling off.  5. Suitable for water tanks and all small tropical fish tanks.  Specification: Condition: Material: Plastic + filter Cotton Color: As Pictures Shown Type: XY-2880, XY-2881, XY-2882, XY-2883, XY-2885(Optional) XY-2880 fit fish tank: ≤80L   XY-2881 fit fish tank: ≤100L XY-2882 fit fish tank: ≤200L  XY-2883 fit fish tank: ≤250L XY-2885 fit fish tank: ≤350L Weight: Approx.168g~439g/5.9oz~15.5oz Instruction:  1. This product needs to be worked with air pump(the air pump should be above 2W). 2. The air pump should be placed at the top of the aquarium to prevent backflow to the air pump due to power outage,Pls Soaking 5 minutes in the water of the aquarium before use it's good for the Nitrifying bacteria forming colony rinse sponge. 3. Rinse your sponge and use aquarium water. Don't use hot water.  Package list:  1 * Aquarium Filter(Included filter cotton)  2 * Suckers Note: 1. Please allow 0~1 inch error due to manual measurement. Thanks for your understanding. 2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.