The Digital Insulation Resistance Tester has safe configuration and improved electro-circuit. It is one new item with more functions, higher precision, and easier operation. It" s also one quake-proof, dust-proof and damp-proof tester for outdoor use. Features: Capability: Can do the test at several test voltages: 100V, 250V, 500V, 1000V; voltage below AC750V can be tested; with resistance measurement ranging from 1 M Ohm to 20 G Ohm . Practical Function: Auto switch the range when measuring resistance; data hold feature; low battery reminder and high voltage indicator. Large LCD Display: Equipped with a 3 1/2 digits big LCD display with max value 1999, easy to read. Safe to Use: Rugged housing is dust-proof and damp-proof; strong load capacity with output short-circuit current about 1.0mA; protective circuit prevents damage from voltage shock. User-Friendly: Turn the rotary switch to select voltage; comes with test leads, alligator clips, and a kickstand on the back. Wide Application: This tester can be applied in all kinds of electric equipment and insulation materials such as transformer, electromotor, cable, switch, appliance, etc. Specifications: Material: ABS Color: Red Size of LCD: 68*44mm / 2.67*1.73in Power Supply: 6 * 1.5V AA battery (Not Included) Working Temperature: 0~40 celsius Relative Humidity: less than 80percent Safety Level: CAT-II 1000V and CAT-III 600V Item Size: 205 * 90 * 55mm / 8.07 * 3.54 * 2.16in Item Weight: 450g / 15.87oz Package Weight: 774g / 27.3oz Package Size: 23.2 * 16.2 * 7cm / 9.13 * 6.37 * 2.75in Technique Index: Test rated voltage: 100V, 250V, 500V, 1000V Output voltage: 90percent ~110percent of the test rated voltage Resistance? ? Measurement range: 1 M Ohm ~ 20 G Ohm ? Resolution: 0.01 M Ohm ? Accuracy: ? 1 M Ohm ~ 200 M Ohm : +/-(3percent of the reading + 5 significant digits) ? 200 M Ohm ~ 10 G Ohm : +/-(5percent of the reading + 5 significant digits) ? 10 G Ohm ~ 20 G Ohm : +/-(10percent of the reading + 5 significant digits) AC voltage ? Measurement range: 1V ~ 750V ? Resolution: 1V ? Accuracy: +/-(2percent of the reading + 5 significant digits) Frequency Response: 40Hz ~ 400Hz Packing List: 1 * Insulation Tester 1 * Storage Bag 1 * Test Leads(pair) 1 * Probe Clips(pair) 1 * User Manual (English)