Auto function stainless steel completely automatic water level control float valve that automatically controls the water level without manual switching! Once it reaches the valve, it would automatically stop refilling water,so it will shut-off when the water reaches the internal float.Easy to installthe male thread are 1/2" and 3/4", we used BSP pipe thread,also the male thread is longer,it's perfectly to fit most of BSP thread connections. If your pipe thread is NPT,you just need to add a few adhesive tape on the male thread, then it works perfectly as well.Wide ApplicationThe floating ball valve is suitable for water tanks water towers/pools /water pools/solar water tanks/water storage, etc. It's used for people to maintain the water level in a garden waterfall, on a yard fountain.Safe and durable materialsWith an exquisite appearance and durable hard shell, it has strong friction and impact resistance, effectively increasing the service life of the product.Working PrincipleWhen the water level in the water tower drops, the floating ball falls, and the pressure of the water in the water pipe is used to open the plunger with the sealing silicone surface in the valve body, the valve body starts the water supply: when the water level in the water tower rises, the floating ball floats up, and the connecting rod drives the plunger.