Please note: the physical slightly color difference or difference, does not affect the use, please do not mind, thank you! Pre-filter sponge: High-density sponge filters debris and pet hair, preventing pump clogging and damage and extending the life of your fountain pump. Warm Tips: Please immerse the filter in water for 2 minutes and rinse thoroughly before use to prevent carbon particles from seeping into the water and your pet enjoys clean and fresh water. Regular replacement: In order to maintain the filtration effect, it is recommended to replace the filter every 2-4 weeks. If you have multiple pets, consider shortening the replacement cycle.<br><br>Colour:Photo Color Material:filter sponge<br><br>Package Contents: 12 x cartridges 6 x sponges<br><br>Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.