ERT 580 Earth Resistance Tester Features: 1. Measures down to 0.01 Ohm. 2. 3 Earth Ranges: 20, 200, 2000 Ohm 3. One test current of 2 mA RMS. 4. Indication if reistance of auxiliary spikes resistance is within range. 5. Two or three-terminal measurement. 6. Three-terminal measurement for earth electrode testing. 7. Large LCD display. 8. Data hold function. 9. Calibration performed with supplied test leads (3 T fully compensated). 10. Meausre eath voltage up to 200V AC. 11. Simple to use and lowe power. 12. Open loop indication with " 1 " (MSD) on display and LED Light off. 13. Lightweight, robust and compact design. 14. Low Battery Indication. 15. " O-Ring" Sealed case for outdoor usage and better protection. 16. Standard accssories for 3T and 2T.