The Fluke 1621 GEO Earth Ground Tester with 3-Pole Fall-of-Potential and 2-Pole Resistivity is an easy-to-use earth ground tester. The first line of defense in detecting reliable ground connections, this unit features basic ground testing methods including 3-pole Fall-of-Potential, as well as 2-pole ground resistance. Its convenient size, rugged holster, and large, clear LCD display make it an ideal field earth tester for most work environments. With a simple user interface and intuitive functionality, the 1621 is a handy tool for electrical contractors, utility test engineers and earth ground specialists.