[Compatibility]perfectly for 135 fl oz/4L wilreless cat water fountain.<br> [ Triple Filtration System]Cat water fountain filters come with 3 layer filtration system, high density cotton can fliter hairs and debris, 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.<br> [Filter Sponge& Pump Sponge]High density pre-filter sponge can further filter out impurities, fully leverage the filtering effect; High density pump sponge can filter impurities, preventing them from entering into water pump, it can help extend pump life.<br> [Replace Filter Regularly]Suggest replacing the filter and sponge every 2 to 4 weeks; Please change them more often if have multiple pets.<br> [Warm Tips]Before replacing the filter, please soak the filter for 5 minutes and thoroughly rinse it before use, which prevent carbon dust from shedding into water, keep water clean.<br> <br> Product Benefits: Removes impurities<br> Colour:Photo Color<br> Material:Polyester<br> Specification:12Set<br> <br> Package Contents:<br> 12 x Replacement Filters<br> 12 x Filter Sponges<br> 12 x Pump Sponges<br> <br> Only the above package content, other products are not included.<br> 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.