Encouraging your cat to drink more water helps prevent crystal formation that can lead to urinary diseases. Because the body uses water continuously, your pet's supply of water must be constant. The Catit Design Fresh & Clear Drinking Fountain provides an indoor source of moving water that will encourage your pet to drink more. It provides the kind of clean, oxygenated water your pet is looking for, and needs. The Catit Design Fresh & Clear Drinking Fountain holds 64 fluid ounces, eliminating the need for daily refilling, and assuring your pet of a continuous supply of fresh, cool, clean water. Easy to clean and maintain its energy-efficient, low-voltage system (12 Volts) consumes less than 4 watts (less power than a night light). The Catit Design Fresh & Clear Drinking Fountain is also suitable for puppies and small dogs. Replacement filters for the Catit Design Fresh and Clear Drinking Fountain are sold separately.