Features: 1. Monitors working voltage with true RMS measurement. 2. Operating mode can be selected via rotary knob. 3. High accuracy with 1% voltage measurement accuracy. 4. LED indicator shows relay status for clear and convenient operation. 5. Compact design with 18mm width, suitable for 35mm rail mounting. 6. Suitable for overvoltage protection of electrical equipment or compressors, and emergency/backup power switching control. Specifications: Function: Voltage monitoring Power terminal (monitoring terminal): A1-A2 Rated power supply voltage (Optional): #1: AC220V #2: DC12V #3: AC/DC24V-48V #4: AC/DC110V-240V Rated power frequency: 45Hz-65Hz Rated insulation voltage: 460V Hysteresis value: 5%-20% Power indicator: Green LED Output relay indication: Red LED Action delay time: 0.1s-10s, ±10% Voltage measurement error: 1% Power-on delay time: 0.5s Knob setting accuracy: 1% Reset time: 1s Temperature fluctuation error: 0.05%/°C at 20°C Output: 1 x SPDT Contact rating: 10A/AC1, 250VAC / 24VDC Minimum switching power: 500mW Mechanical life: 10,000,000 cycles Electrical life (resistive load): 1,000,000 cycles Operating temperature: -20°C to +55°C Storage and transportation temperature: -35°C to +75°C Installation method: 35mm rail installation Protection level: IP20 Installation location: Any Installation altitude: Up to 2000m Pollution degree: 2 Wiring capacity: 1 x 2.5mm² or 2 x 1.5mm² Dimensions: 90mm x 18mm x 64mm (Approx. 3.5 x 0.7 x 2.5in) Compliance standards: GB14048.5, IEC/EN 60225-1 Package list: 1 x Relay 1 x User manual