7-piece set: Set consists of 3 activated carbon filters, 3 pre-filters, and 1 pump filter suitable for: ne&no® ceramic drinking fountain The set contains all the replacement filters needed for the ne&no® ceramic drinking fountain: Pre-filter: for coarse dirt, provides an additional protective barrier, and prevents dirt from entering the water Activated carbon filter: reduces odors and prevents the accumulation of bacteria Pump filter: protects the pump from dirt and pet hair FOR CLEAN WATER: the filter cleans the water by removing impurities, suspended particles, and odors, ensuring fresh, clean water for your pet. HYGIENIC: in addition to pure filtration performance, the activated carbon also filters harmful bacteria and toxins from the water. USAGE: it is recommended to change the activated carbon filter together with the pre-filter every 2-3 weeks, depending on usage and the amount of impurities in the water. The pump filter should be changed every 2-3 months. If the water flows more slowly or the fountain develops unpleasant odors, it is time to change the filter.