1. Wide range of measuring voltage can test up to 1000G (Max 2000G) insulation resistance 2. Three and a half bit LCD digital display of insulation resistance value 3. automatically shift resistance measuring range 4. environment temperature can be measured 5. self-clocking function short buzz every 15 seconds 6. automatically calculate and save R15S R60S R600S DAR and Polarization Index 7. Output short-circuit current larger than 5mA (meet fast charging request to capacitive load) 8. strong anti-interference ability stable and reliable reading 9. perfect protection safe for operation 10. powered by rechargeable Li-battery auto power off when battery energy is not enough