This sensitive automatic indicator is your answer to controlling granular, free-flowing materials. Bin-Master Indicators can be used in single or multiple units to provide automatic on-off switching, activate relays, actuate audible or visual signals and many other control tasks. Ideal in supply bins, storage silos, conveyors and elevators. Easily installed, these indicators consist of a sensitive 22 amp micro-switch inside of a heavy cast housing. The switch is activated when material presses against a flexible neoprene diaphragm. Operates on 125V, 250V or 460V A.C.