Charcoal Water Filters Replacement for Pioneer Pet Ceramic & Stainless Steel Fountains By NISPIRA - 12 Filters 12 Packs premium charcoal water filter by NISPIRA replace Pioneer Pet water filters Compatible with Pioneer Pet Ceramic Fountains, Pioneer Pet Stainless Steel Fountains, Petco Premium Ceramic Fountains Replace filter every 2 to 4 weeks. Individual sealed to maintain the high quality 3-Layer Filtration with Granulated Carbon and Duo-Density Polyester Pads