The TOMZN TOVPD1-63-EC Adjustable Over-Voltage and Under-Voltage Protector Relay safeguards your electrical systems from abnormal voltage fluctuations. It automatically disconnects power during over- or under-voltage conditions, then restores it once voltage returns to normal. Suitable for residential, industrial, and automation systems, this protector features adjustable thresholds, delay time control, and a digital LED display for real-time voltage monitoring.