Boajf Automatic Water Dispenser for Dogs, Auto Water Dog Bowl with Drain Valve, Livestock Large Waterer 2 Gallon with Float Valve, Stainless Steel Water Trough with Hose Connector for Horse, ChickenDrainage SystemThe bottom of the automatic dog water dispenser 3 Gallon is equipped with a drain valve. The auto fill dog water bowl is controlled by the water valve for sewage discharge. It is easy to clean and hygienic Water Supply SystemAutomatic pet water dispenser with floating valve, and automatic chicken waterer works by using buoyancy principle. Compared with traditional automatic livestock waterer, it can achieve a water saving efficiency of