Features: Digital display for DC voltage detection with relay control output. DC 680V relay interface board includes 2 buttons for easy operation. Equipped with a clear LED display for convenient voltage monitoring. Adjustable voltage detection range: DC 099.9V. Relay activates when the measured voltage falls below the lower limit or exceeds the upper limit. Ideal for voltage detection switching, battery over-voltage/under-voltage protection, or discharge monitoring. Includes a protective cover. Specifications: Material: PCB + ABS Working Voltage: DC 680V Voltage Detection Range: DC 099.9V Accuracy: 0.1V Working Current: - 8mA/24V (relay open, LED off: approximately 4mA/24V) - 58mA/24V (relay closed) One set of changeover contacts (normally open/normally closed, NO/NC) Contact Load: - NO: 30A/250V AC or 30A/30V DC - NC: 20A/250V AC or 20A/30V DC Note: Due to the risk of high-voltage DC arcing damaging relay contacts, for voltages above DC 60V, the load current should be less than 10A. Contact Resistance: 100m (1A, 6VDC) Mechanical Durability: 10 million operations Electrical Durability: >100,000 cycles (20A, 250VAC) Operating Temperature: -40C to 85C Item Size: 9.4 x 5.2 x 3cm / 3.7 x 2.05 x 1.18in Package Size: 9.5 x 6 x 3cm / 3.74 x 2.36 x 1.18in Package Weight: 85g / 3oz Package List: 1 x Relay Switch Controller