Green AD16-22DSV AC60-500V 22mm LED Digital AC Voltmeter ' Features: Lens Material: PC; Lighting Source: LED; Volt.: 60V--500V; Nature of supply: AC ; Rated Temp : T90; Life of continuous working: Typically over 30,000 hours. The end of life for a lamp is not usually a sudden failure. Main technical parameters Environmental Temperature: -25+55; Working under vibration frequency 2-80Hz,acceleration at 0.7g; Relative Air Humidity: ≤98%; Pollution rank is three grade and installation category is III; Protection Degree: Head IP65 Voltage of working frequency: 2.5kV (AC valid value), 1min; Leakage Index: CT1≥100; Frequency: AC 50-60Hz