The Model 2681 Voltage Band Monitor is a dual set-point voltage monitor. Input voltages between the upper and lower set-points will cause the output contacts to pull in (contacts 1 & 3 closed) and the LED indicator to illuminate. Input voltages above or below the set-points will cause the output contacts to drop out (contacts 1 & 4 closed) and extinguish the LED indicator. The Model 2681 is available in AC or DC versions. AC models of the 2681 are not frequency sensitive and can be used on systems from 50 to 400Hz. The voltage set-points are screwdriver adjustable over a wide operating range. The SPDT ouput configuration is identical to the configuration of general purpose relays. This unit requires a standard 8- pin socket for mounting.