The Fluke I3000S FLEX-24 24 in. AC Current Flex Clamp/BNC, 30A-3000A AC Switchable uses the Rogowski (air-cored coil) principle and can be used to measure three ranges of currents up to 3000A, when used in conjunction with oscilloscopes, recorders or data loggers. The flexible and lightweight measuring head allows quick and easy installation in hard-to-reach areas without batteries or an external power source. This clamp fits around large conductors.