Features: Replacing the filter element of paper filter is a part of the daily maintenance of the tank. Regular replacement of the filter element may be costly. These clean and reusable foam filters will reduce your cost. The initial cost of the cartridge is slightly higher than that of the cartridge, but the cartridge life is longer over a long period of time. This foam filter will be more durable than the carton, and it can be washed and reused many times. It is suggested that a carton should be replaced every week, and these bubbles can be cleaned and put back simply. You should see foam filters last for about 2 months. Specifications: Type: filter sponge Material: Sponge Quantity: 1pc Colour: Sky Blue Size: A: 73*108*108mm/2.87*4.25" B: 102*90*90mm/4.02*3.54" C: 200*100*100mm/7.87*3.94*3.94" Notes: 1. Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Thank you! 2. Please allow 1-3cm measuring deviation due to manual measurement