Features: This insulation resistance tester can measure insulation resi stance, AC voltage, etc. High degree of accuracy, stable performance, easy operation and reliability. Support automatic measurement, low battery indication, LCD backlight, alarm light display, alarm buzzer. Widely used for insulation resistance measurement for insulation materials and various kinds of electric equipments such as transformer, electric machines, cables, switches, electrical appliances. I is a ideal tool for electric equipment maintenance, testing and inspec tion. Specification: Display: LCD, 1999 count Overload Indication : "＞5.5GΩ" for insulation resistance measurement; "OL V" forvoltage measurement. Accuracy: ±(a% reading + digits); calibration per year Working Temperature: 0-35℃ Working Humidity: ≤75% Working Altitude: 2000m Storage Temperature: -20~60℃ Storage Humidity: ≤80% Battery: 6pcs x 1.5V Battery (NOT included) Size (Approx.): 150*100*71mm/5.9*3.9*2.8in Weight (Approx.): 837g/29.5oz Insulation Resistance Measureme nt Rated Voltage 100V 250V 500V 1000V Test Range 0.00MΩ~5.5GΩ （When It is about less than 4.0MΩ, buzzer outputs alarming sounds）. Note: (100V)0.00MΩ~100MΩ Opened Voltage DC 100V±10% DC 250V±10% DC 500V±10% DC 1000V±10% Rated Test Current When load is 100KΩ, the rated testing current is 0.9mA ~1.1mA. When load is 250KΩ, the rated testing current is 0.9mA ~1.1mA. When load is 500KΩ, the rated testing current is 0.9mA ~1.1mA. When load is 1MΩ, the rated testing current is 0.9mA ~1.1mA. Shorted Current About less than 1.8mA. Accuracy 0.00MΩ~99MΩ: ±（3%+5digits）; 100M ~5.5GΩ: ±（5%+5digits） Voltage Measurement AC Voltage Test Range 30V~750V(50Hz/60Hz) Resolution 1V Accuracy ±（2%+3digits） Package List: 1 x Insulation Resistance Tester 2 x Test Lead 2 x Crocodile Clip 1 x Black Bag 1 x Gallus .