The DP-4 is a new, affordable dosing pump with 4 dosing heads. You can program each pump to come up to 24 times a day and dispense a precise amount of solution, which allows a user to keep their tank parameters stable, and removes the need for mixing supplements daily. The controller is easy to use and advanced, and each pump can be programmed individually. The DP-4 is perfect for any tank, as it allows for dosing in both large and small increments. The DP-4 comes with a power supply and is plug and play after it is calibrated with a 100 ml graduated cylinder or measuring cup (not included). Usage Guideline: Only for indoor use, must avoid waterproofing. Do not use for liquid with easy corrosion, easy crystal. Do not put the inlet hose the liquid with easy corrosion, easy crystal. Before use, please must make full of the inlet & outlet hose with liquid via manual mode, and calibrate the flow rate of each pump. To ensure the precision on the work process. Plug off the power if need to adjust the feeding interval time.