The Drinkwell® Outdoor Dog Fountain is their largest capacity pet fountain, offering 3.5 gallons of fresh, filtered water to your pet. With its patented free-falling stream of water, pets are encouraged to drink more, and they get the cleanest, freshest-tasting water. This system is perfect for large dogs or multi-pet homes. Made with high-impact UV-resistant plastic, this durable fountain can be placed inside the home or outdoors. The dual filtration system removes small particles and catches dirt, hair, and other debris that larger dogs tend to leave behind.