Automatic Operation: The float valve automatically fills your tank, water tower, fountain, or water trough when the water level drops below the valve level. Once the water level reaches the valve, the filling stops automatically and shuts off when the water reaches the internal float. Your tank always remains full. Easy Installation: This automatic water level control valve is compact and easy to install. The male thread is 1/2". No Electricity RequiredA built-in float allows water to flow up to a certain level. Once this level is reached, the float is pushed upwards by buoyancy and the water stops flowing. When the water level drops, the float opens again and the water starts flowing again. So no electricity is required. Widely UsedIt is used to maintain the water level of a garden waterfall, a garden fountain, a gutter project, and using the automatic pool float for automatic closing of swimming pools, chicken coops, automatic waterers for chickens, livestock and drought, outdoor rain barrels, fountain fillers, etc. SafetyThe float body is made of stainless steel, making it an environmentally friendly float. CautionIf you use an automatic float indoors, make sure you have an emergency overflow system. Automatic floats can eventually fail and cause flooding. It is always best to set the lowest water level. flow rate necessary to maintain the water level.