12 Packs premium charcoal water filter compatible with Drinkwell Pet water fountains Compatible models: Drinkwell 360 & Drinkwell 360 Stailess Multi-Pet Filters Food grade activated carbon water filter removes bad tastes and odors from water, keeping it fresh; change every 2-4 weeks to maintain water freshness Nispira branded filters contain 50% more carbon than generic brands for better and longer-lasting filtration 100% customer satisfaction guaranteed. Quality meets or exceeds leading national brand 12 Packs premium charcoal water filter compatible with Drinkwell Stainless Multi-Pet and Plastic 360 Pet Fountains