The Model 157 Register is a "non-resettable" totalizer that provides an increasing cumulative reading. An input shaft connected to the register change gear drives the register. There is a 1:1 ratio between the input shaft and the first wheel. To measure in increments of more than a single unit, the Model 157 uses "fixed zeros" to the right of the first wheel. A Model 157 Register reading in gallons or pounds is a function of the flowmeter's gear train ratio and the ratio of the two change gears. For each complete revolution of the pointer, the right hand wheel on the totalizer will rotate one complete revolution.