DUPLEX HEAD METERING PUMP: The Blue White C1700N chemical feeder has twin, independently controlled, Heavy Duty Cartridge Valve Heads. This design ensures efficient use of motor power, and is particularly important for overcoming back pressure. The alternating strokes of the C1700N mean double the injections per minute. This is of significance to those who require a pump approaching a constant, even feed rate. The versatile C1700N is suitable for use in a variety of applications. For example, it will inject different amounts of like chemical into separate systems or feed two different chemicals into the same system (blend).