Drinkwell® The Original Pet Fountain is perfect for single-pet households! It features the Drinkwell®-patented free-falling stream of water and a large charcoal filter to remove bad tastes and odors, giving your pet the best possible and most appealing way to stay hydrated. The Original Pet Fountain not only satisfies a pet’s preference for running water and need for proper hydration, but is also convenient for owners. The easily-maintained fountain has a 50 oz. capacity and can hold up to 120 oz. of water (with the use of an optional reservoir). Best of all- the Drinkwell® Pet Fountain keeps pets off of counters and out of sinks and toilets! Drinkwell fountains are compatible with all US 110v outlets only and are not to be used with 220v international voltage.