Features: 1. High quality: Our aquarium filter cotton is made of high-quality sponge and has good filtration effect. Biochemical cotton filters clean dirt and stabilizes water quality. 2. Protect shrimps and fish: Multi-layer filter cotton filters to completely avoid sucking shrimps and fish. 3. Reduce air pump noise and consume less power. Increases oxygen solubility without producing operating noise. Suitable as external filter or above purification unit. 4. Increase the oxygen content of the aquarium: Harmful substances are decomposed by nitrification on the sponge and converted into substances harmless to fish and returned to the aquarium. Suitable for storing and observing different fish. 5. Widely used: This aquarium filter is small and can be easily hidden behind plants. It fits in any corner and is perfect for shrimp tanks, breeding tanks, beta aquariums, water tanks, turtle tanks, aquariums, goldfish, juveniles or other fish. Description: Material: Sponge Model: SG-2812 replacement cotton Package includes: 2x sponge filters Note: 1. Please allow some errors due to manual measurement. Please make sure you don't mind before bidding. 2. Due to different monitors, colors may vary, please understand. Hello, please pay attention to your shipping address when purchasing products. If your delivery information (such as name, street, house number, doorbell/box without name, etc.) is incorrect, the order will not be delivered correctly. )