Single Stage Liquid Level Switches in Housings are designed to shut down machinery or turn on warning devices when the liquid supply fails or recedes to a predetermined level.  They can be wired to flash a warning light, sound a howler, shut down a machine, or signal a computer.  This is especially helpful in unattended automated plants.  The units can be used with large bearings, gear cases, transformers, circuit breakers, oil tanks, and cutting oil reservoirs on screw machines, along with many other applications.  The distance between centers of the mounting holes is 4 3/8".