American Marines PINPOINT pH Controller. PINPOINT pH Controller is an inexpensive yet rugged controller, which includes the appropriate probe and calibration fluids. This device will automate another electrical device such as a calcium reactor or magnetic solenoid for the addition of CO2 into an aquaculture or process system. This full feature controller will handle up to 5 amps. Comes complete with probe and calibration fluids. The PINPOINT pH Controller is perfect for the freshwater planted aquarium keeper as well as the serious saltwater hobbyist. Will control pH in both a downward and upward direction. The user will select his or her own set point and any range of acceptable pH around this set point. 110 VAC operation. Calibration fluid pH probe 2 year manufacturer`s warranty.