MCDONNELL & MILLER FS-254 Flow Switch Universal design serves the widest variety of applications For starting or stopping electrically operated equipment such as signal lights, alarms, motors, automatic burners, metering devices and others Replacement for common flow switches from Johnson/Penn, Potter/Taco, Watts, Hydrolevel and other manufacturers 1″ NPTM Pipe Connection Sensitivity adjusting screw makes flow adjustment easy Single pole, double throw snap switch EPDM O-ring sealed Four stainless steel paddles included 1″, 2″, 3″ & 6″ (25, 50, 80, &