The PetSafe Drinkwell 3.7 Litre Pet Fountain features a free-falling water stream with adjustable flow control. Choose from nearly silent circulation on the lowest setting to a tranquil stream on the highest. The replaceable charcoal filter removes bad tastes & odors from the water while the replaceable foam filter catches hair & debris. The receiving ramp reduces splash and the constant water circulation inhibits bacteria growth. This fountain was specifically designed with no hard-to-reach crevices to clean, allowing you to spend more quality time with your pet.