Features: Stable performance. 35mm standard rail installation. Intelligent LED screen voltage current protector. Real-time clear display working voltage, you can manully cabibrate the voltage if not correct. It can cut off the pwoer supply instantaneously when the- line has overvoltage or undervoltage overcurrent faulty, so as to protect the electrical equipment from being damaged. Specifications: Material: Plastic Size: Approx. 8.5x5x3.6cm/3.35x1.97x1.42in Type: 40A/63A Note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1x Protective Device