The Fluke 3310-PR-TF-II 24 in. Thin Flexible AC Current Clamp for Model 1750, 5000A AC utilizes the Rogowski principle. The 3310PRTFII is designed to measures current from very low frequencies up to the 50th harmonic of a 50/60 Hz power supply. The flexible and lightweight measuring head allows for quick and easy installation in hard to reach areas and around large conductors. It includes a 24 inch long connection cable.