The Sensus SR II® is for measurement of cold water flow usage in residential services. Water flows through the meter’s strainer and into the measuring chamber where it drives the piston. The hydrodynamically balanced piston oscillates around a central hub, guided by the division plate. A drive magnet transmits the motion of the piston to a driven magnet located within the register. The driven magnet is connected to the register gear train. It calculates the rotations into volume totalization units displayed on the register LCD.