The BasicLine BL550 is a highly compact setpoint alarm relay with changeover output contacts. It's commonly used in simple monitoring and control of standard signals and has NC/NO changeover. Input signals, switching hysteresis and delay are adjustable using DIP switches. This Knick unit has 3-way isolation as well as comes with some of the highest reliability in the industry backed by a 3 year warranty. UL approved and CE compliant.