Description: Biochemical Sponge Filter, durable to use and easy to replace, suitable for all types of water As the water passes through the pores, the sponge will trap debris from your tank, leaving the water crystal clear. Effectively improve water quality. Cultivating the nitrifying bacteria, will give you superior biological filtration in your tank. This inter filter is noiseless and energy saving. Only requiring an air pump and airline tubing (sold separately) to work. These create numerous minute bubbles for increased oxygen flow. Betta, fry and other small fish will NEVER get sucked up into the filter. Fish friendly, you can feel relieved to use it Aquarium inter filter can be used for many times, easy to clean Specification: Material: Sponge+Plastic XY-2885 Total Height:approx.21.5-35cm/8.47-13.78 inch,Bottom Length:approx.13.5cm/5.31 inch,Sponge+Filter Box Height:approx.15.5cm/6.1 inch XY-2883 Total Height:approx.21.5-35cm/8.47-13.78 inch,Bottom Length:approx.8.8cm/3.46 inch,Sponge+Filter Box Height:approx.15.5cm/6.1 inch XY-2882 Total Height:approx.19-29.5cm/7.48-11.62 inch,Bottom Length:approx.11.3cm/4.45 inch,Sponge+Filter Box Height:approx.12cm/4.72 inch XY-2881 Total Height:approx.19-29.5cm/7.48-11.62 inch,Bottom Length:approx.7.5cm/2.95 inch,Sponge+Filter Box Height:approx.12cm/4.72 inch XY-2880 Total Height:approx.15.5-22cm/6.1-8.66 inch,Bottom Length:approx.14.5cm/5.71 inch,Sponge+Filter Box Height:approx.10.5cm/4.13 inch Package Includes: 1 Piece Aquarium Filter Note: Before using the filter, soak in aquarium water for 5 minutes Use aquarium water to wash filter sponge, DO NOT use hot water Since the size above is measured by hand, the size of the actual item could be slightly different from the size above. Due to the lighting effects, monitor settings, etc. There could be some slight difference in the color tone of the pictures and the actual item