[Compatibility]Rplacement filters and pre-filter sponges set, perfectly for 84oz or 2.5L, blue and grey automatic cat water fountain. [ Triple Filtration System]Cat water fountain filters come with 3 layer filtration system, high density cotton non-woven fabric 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, can keep water clean, fresh and tasty all day, and reduce the risk of urinary tract infections. [Pre-Filter Sponges ]High density pre-filter sponge around the pump, can better filter impurities, preventing them from entering into water pump, it can help extend the pump life. [Replace Filter Regularly]Suggest replacing the filter every 2 to 4 weeks and replace the sponge every 4 to 8 weeks Please change it more often if have multiple pets. [Warm Tips]Before replacing the filter, please soak the filter in water for 2 minutes and then rinse it thoroughly under running water, which will prevent carbon dust from shedding into water, keep water clean. Filters for 84oz or 2.5L Pet Fountain Colour:As Shown Material:Polyester Package Contents: 8xReplacement Filters 8xPre-filter 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.