The Com-Power PS-400 near field probe kit is used find the source of EMI radiation from products that fail EMC compliance testing. The cause of the the higher emissions must be investigated and fixed to make the product compliant. Finding the source of the emissions at the circuit level is not possible using an antenna. Near-field probes let you "sniff" around the circuits, cables, and enclosures to find the source. The PS-400 Near field has three probes. Two E-Field probes and a H-Field Loop Probe.