LiquaGen Super Flow Reverse Osmosis/Deionization Water Filtration System + Pressure Gauge & Float Valve. This product is great for aquariums, laboratory testing, and other applications for pure water. GPD means Gallons Per Day & if in doubt about the GPD of your system please contact us Manual Flush Valve makes this system superior to any other RO/DI system in the market by increasing the life of the unit, reducing possible leaks, and saves you valuable time when flushing the system every few months. High Rejection Reverse Osmosis (RO) Membrane. Film by GE USA 2 year manufacturer warranty; Lifetime customer support