Float Valve - Nickel Plated. Choose either Vertical or Horizontal mount. 1/4" tube compression connector. Excellent for aquarium owners or orchid growers. If you use a static atmospheric tank to collect your RO water and want a way to automatically turn off the RO system when the tank is full, this float valve is for you. When the valve closes it will trigger the auto shut off valve ASO in RO systems and turn it off. The float measures approximately 3" long x 1 3/8" diameter. Easy to install and use.