3.2 Liter super large capacity water tank, ideal for medium to larger-sized pets. Constantly flowing, triple-layer filtration fountain keeps the water, fresh and healthy, and encourages pets to drink more often. Automatic shut-off when the water level is low, this smart dry-run protection with ultra-quiet design makes home use pleasant and worry-free. The filters are compatible with the Smart Foutain Plus 3.2 Liter fountains only, not compatible with 2-liter or 1 Liter Mini fountains.