Compatible : This fountain filter is only compatible with NPET WF050 tansparent pet fountain
4 Packs in One Set : Set of 4 filters compatible with the NPET WF050 cat fountain, which is worthy with such high quality
Easy to Use : Rinse the filter with water about 10 mins before use, replace it every 4 to 6 weeks to fresh the water.
Usage Time NPET suggests to replace the filter every 4 to 6 weeks. It depends on your use.
Fresh Water : NPET uses high-density and high-content activated carbon filter whcih can effectively maintain water quality, increase oxygen content to keep cats healthy.