An orifice selector module for use with flow gauges in a sprayer environment. The orifice selector module is retrofit into existing or new flow gauge assemblies and is placed in line between the spray nozzles and the flow gauges. The orifice selector module includes a rotatable cap which rotates a rotor which in turn rotates an orifice plate which features numerous orifices of different sizes. These orifices can be switched on the fly manually by the vehicle operator to increase or decrease flow through a particular hose from a particular flow gauge.