Features: The pet water fountain needs to replace the carbon core filter regularly to keep the water fresh. A set of 4 filters and 4 sponges are compatible and easy to replace, bringing more protection to your pets. Three-layer filtration, blocking hair debris, removing residual heavy metals, allowing pets to drink clean and fresh water throughout the day. A filter is a must-have accessory for a pet fountain. Own it, provide a healthy environment for your beloved pets. Remove peculiar smell, soften water quality, easy to disassemble and wash, help pets increase drinking water and maintain healthy and good living water. Precautions: Soak the filter element in a clean bowl for 5 minutes Note that the filter element must be fully soaked before turning on the fountain; otherwise, the water may not be able to diffuse through the filter and cause overflow, please do not soak the filter in the fountain tank to avoid dust on the surface . Specification: Material: activated carbon Size: 6.89*3.54in/17.5*9cm Color: as picture shown Package Includes: 4pcs (1 set) Notes: Please allow minor errors due to manual measurement. The colors may be a little difference for the different monitor display.