Keep your pet cool and hydrated, especially during warmer months, with Petmate's Deluxe Fresh Flow Pet Fountain. With its continuous flow or circulating, oxygenated water, your pet will have access to fresh water all day! Ideal for multiple pet households. Choose from two sizes: large (108 oz.) or jumbo (216 oz.). For maximum freshness, change the charcoal filter every 30 days to ensure your pet's water is as fresh and clean as possible.