[Compatibility]Rplacement filter [Quadruple Filtration System]Cat water fountain filters has 4 layer filtration system. Friendly pp shell, stop hairs and large particles, high density cotton can fliter hairs and residue, keep water clean; Activated carbon can remove chlorine and odor, purify and freshen water; Ion exchange resin can filter heavy metals and improve the taste, which can encourage pets to drink , and reduce the risk of urinary tract infections. [Pre-Filter Pump Sponges ]High density pet fountain pump filter, can capture hair and debris, preventing them from entering into the water pump, can protect the water pump more effectively and extend the life of the fountain. [Replace Regularly]In order to achieve better filtering effect, we suggest replacing filters and sponges every 2 to 4 weeks, please change it more often if your have multiple pets. [Warm Tips]Before replacing the filter, please soak filter in water for 2 minutes and then rinse filter thoroughly, which will prevent carbon dust from shedding into water, keep water clean and fresh. Color: white+black Material: non-woven fabric Package Contents: 8 x Filters 8 x Sponges 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.