The I400 is a Fluke AC current clamp designed to extend the measurement capabilities of digital multimeters by enabling AC current measurements up to 400 A in a compact form factor. It features a nominal current range of 400 A with a continuous operating range from 1 A to 400 A, a maximum non-destructive current rating of 1000 A, and a basic accuracy of 2% +0.06 A across the 45-400 Hz frequency range. The clamp accommodates conductors up to 32 mm (1.25 in) diameter or busbar sizes up to 750 MCM, with a useable frequency range of 5 Hz to 20 kHz and an output level of 1 mA/A. Safety-rated to CAT IV 600 V and CAT III 1000 V per EN61010, the I400 is ideal for electrical troubleshooting, maintenance, and field measurements where portable AC current monitoring is required.