[Compatibility]perfectly for 2.2L/73oz stainless steel pet water fountain; [ Triple Action Filter]Pet fountain filters come with 3 layer filtration system. High density cotton layer, coconut shell activated carbon and ion exchange resin, they can filter hairs, debris and heavy metals, and improve the taste of the water. [Pre-filter Sponge & 8D Filter Sponge]High density pre-filter sponge can further filter out impurities, fully the filtering effect; High density 8D filter sponge can filter impurities, preventing them from entering into pump, it can help extend pump life. [Easy to use]We advise you to replace filter and sponge every 3-4 weeks to keep the water clean; Please change them more often if you have multiple pets. [Warm Tips]Before replacing the filter, please rinse filter 3-5 minutes thoroughly with drinkable water, which will prevent carbon dust from shedding into water, keep water clean. Product Benefits: Removes impurities Colour:Photo Color Material:Polypropylene (PP) Specification:5Set Package Contents: 5 x Filter 5 x Sponge 5 x 8D Sponge 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.