Dwyer Instruments - Controls and Instrumentation
They are known for the Magnehelic differential pressure gages, Photohelic pressure switch/gages and varied types of flow-meters and valves.

Series MPC Pump Controller
"Incorporated in the MPC is programmable level differential for on/off control of one or two pumps, valves, or other devices through two SPDT relays. Also featured are two additional programmable alarm contacts with front alarm light indication."
Dwyer Instruments, Inc.
102 Indiana Hwy. 212 (P.O. Box 373) Michigan City, IN 46360 (46361) USA