Feature: 1. AUTOMATIC RESET: The protector has an automatic reset function, which can prevent long term power failure and ensure its service life. 2. QUICK RESPONSE: The protector has a quick response speed and sensitive internal components, saving you working time and making it more practical. 3. DIGITAL DISPLAY: The digital display screen displays the working voltage and current in real time, you can monitor the abnormality and use it with confidence. 4. EASY INSTALLATION: This 3 phase protector is installed by DIN rail, which is simple and easy to operate, and is stable and firm after installation. 5. SAFE TO USE: When the protector is overloaded, it will automatically cut off the power, and the power will be supplied normally within the specified power, so as to prevent the danger of overvoltage and undervoltage. Specification: Item Type: 3 Phase DIN Rail Voltmeter Material: PC Model: CHSG 40 Load Current: 1-63A Overvoltage Setting Value: AC390-500V Undervoltage Setting: AC370V-140V Power Off Time (Set 1-300s): 5-300S(V), 30-300S(I) Installation: Approx. 35mm x 1.4in DIN rail. Package List: 1 x 3 Phase DIN Rail Voltmeter1 x Instruction