Feature:1. Smart Monitor: Able to better monitor the single phase over voltage and under voltage errors in real time to protecting the circuit.2. Higher Safety: With 300-490V AC wide working range and high accuracy, the over under voltage protector enables good electrical safety.3. Reliable Work: The automatic recognition on AC and DC voltage requires no switching, while the auto resetting makes operation easier.4. Clear Display: LCD digital display can clearly show the voltage value, error status and setting parameters, very simple and reliable.5. Easy to Install: Modular structure together with compact size and light weight will bring more convenience to the rail installation.Specification:Item Type: Over Under Voltage ProtectorModel: STVP-931Material: ABSRated Supply Voltage: 380VACWorking Range: 300~490VACWorking Frequency: 50HzVoltage Hysteresis: 10VAsymmetric Hysteresis: 2%Automatic Reset Time: 1.5sPhase Loss Tripping Time: 1sMeasurement Error: 1% with adjustable voltage range. Protection Class: IP20Working Environment: -25~65, 85%RH, non condensing. Mechanical Durability: 1,000,000 cycles. Dielectric Strength: >2kVAC 1min.Package List:1 x Over Under Voltage Protector1 x User Manual