Unique technology: uses high-density high-density activated carbon filter, and the filter structure is combined with high-density white filter to achieve multiple filtrations, which can effectively maintain water quality, increase water oxygen content and improve pet health protect. 6 packs in one set: You get 6 pieces of pet fountain filters with one order, which is worth high quality. Filters: You can decorate your fountain with filters, catch your cats, watch out the dogs coming to drink water. Compatible:This replacement filter is only compatible with the NPET WF050TP WF100 transparent fountain. Easy to use:Rinse the filter thoroughly with water before using, replace -it every 2 to 4 weeks to maintain the freshness of the water.