My cats took a little time to get used to this, but now they prefer it over their old water dish.Pros:Water is constantly moving. Animal can drink from the bowl or a flowing trickle of waterWater is filtered.Holds plenty of water for two cats (or more)Can go several days without changing the water.Quiet operation.Variable flow rate.Cons:proprietary filter is a bit expensive. A refillable carbon bag would have been better.Comment:This unit arrived with a defect: the transformer in the wall plug made a loud humming noise, 60 Hz. The company replaced it quickly and without hassle.