Features: The device can be adjusted to protects against overvoltage, undervoltage, and other problem, ensuring that your circuit is safe and stable. This product is designs to protects your circuit from damage caused by power fluctuations, ensuring that your equipment stays safe and functional. The relays feature of this product allows you to control the flows of power to your circuit, making it easy to troubleshoot and fix any problem. High flame retardant insulation shell, with good impact resistance, heat resistance, and low temperature resistance. The LCD display is clear and easy to read, and the data can be read directly. Specifications: Component: Plastic shell Current: 40/63A (optional) Size: about 3.9x8.1cm/1.54x3.19inch Effective voltages ranges: AC80-300 Effective current ranges: AC0.1-63.0A Frequency ranges: 40-70Hz Screen refreshes rate:>1000Hz Overvoltage and undervoltage hysteresis: 5V Timer ranges: 1-999S Action time: 0.1-10S Package Includes: 1pc Over voltages and Under voltages Protective Device note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to difference between different monitors, the picture may not reflect the actual color.