PetSafe Drinkwell Premium Filters 3-pack - replacement carbon filters for fountains, compatible with Mini, Original, and Platinum modelsPetSafe Drinkwell Premium Charcoal Filters are replacement charcoal filters for PetSafe water fountains. The set includes 3 pieces. The charcoal filter keeps the water clean by removing unpleasant tastes, odors, and impurities. Simply replace the charcoal filter during fountain cleaning. Regular replacement every 2 4 weeks is recommended. PetSafe Drinkwell Premium Charcoal Filters are compatible with the following pet fountain models: Drinkwell Mini