Functions: 1.Over-voltage protection. Under-voltage protection 2. Over-current protection. Automatic 3.Voltage display(voltage measurement). Current display (current measurement) 4.Wattmeter kWh Energy Meter Power Consumption 5.Installation:35mm DIN rail. Product Parameters: 1.Rated supply voltage:AC 220V 2.Operation volatge:AC 80-400V(single phase) 3.Rated frequency:50/60HZ 4.Electric current ( A) setting range:1-40A OFF 5.Overvoltage ( U)setting range:230-300V/OFF 6.Undervoltage ( Less than U) setting range:210-140V/OFF 7.Kilowatt-hour protection value:1-9999/OFF 8.Rated current:40A 9. U and Less than U trip delay time:0.5s 10.Reset / delay time:1-600s 11.Voltage measurement accuracy:2%(not exceeding 2% of the overall range) 12.Rated insulation voltage:400V 13.Output contact:1NO 14.Electrical life:100000 15.Mechanical life:1000000 16.Protection degree:IP20 17.Pollution degree:3 18.Operating temperature:-50-55 19.Humidity:50% at 40 (without condensation) 20.Storage temperature:-30-70 size: 8.5 x 3.5 x 6.5cm Material: PC colour: white Package Contents: 1 x Voltage Protector Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.