In- Features: 1. Keep the water clean: the principle of biological filtration and the use of multi-level filtration to cultivate high-density nitrifying bacteria to achieve clean and good water quality stability. 3. Multi-layer design: filter for multiple times, the bottom of the filter is a layer of biochemical sponge, the medium is gas stone, and then the outlet of the funnel is covered, the filtering effect is better. 3. Material: Our biochemical sponge filter is made of environmentally friendly plastic, strong and durable. 4. With suction cup: The filter has a powerful suction cup, which is durable and easy to clean and install. 5. Application: This filter is suitable for ornamental fish breeding, breeding, and young fish cultivation, especially for small fish and fry. Description: The biochemical cotton filter can cultivate nitrifying bacteria and adopts a multi-layer design with a large surface area, which can filter impurities and make the water quality clearer. Specifications: Size: 9.8*3cm Weight: 51g Material: plastic, biochemical cotton Package Included: 1 * Biochemical cotton filter Notes: 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 real object.