Feature: 1. Its multi-porous feature will avoid blockages and provide the largest adhesion area for bacteria. 2. Made of high quality sponge material, large thickness, durable and long service life. 3. Multiple sizes, so you have more choices, choose the most suitable one. 4. Reduce waste water deposition and filter core flow attenuation. 5. Suitable for quicksand filter, excellent water permeability, dense shape makes it effective to avoid residue. Specification: Condition: 100% Brand New Item Type: Aquarium Filter Cotton Material: Sponge Color: Black Suitable for: Quicksand Filter Quantity: 1PCS Optional Diameter: Approx. 120mm, 150mm, 200mm, 250mmDiameter: Approx. 120mm/4.72inch(Suitable for FBF900 Quicksand Filter)150mm/5.91inch(Suitable for FBF1600 Quicksand Filter)200mm/7.87inch(Suitable for FBF2700，FBF5400 Quicksand Filter)250mm/9.84inch(Suitable for FBF10800 Quicksand Filter). Package List: 1 x Aquarium Filter Cotton Note: Using suggestion:1. The quicksand filter is equipped with two separate sponges2. When used, sponge body should be used to separate the internal medium (such as quartz sand, etc.) from the bottom acrylic plate to extend the service life of the equipment3. Please regularly check the use of spongy body, if worn thin please replace