The E-Probe by Colorado Para-Tech claims to be the REM portion of the Mel-REM Meter however this is not quite true. The EM-Probe or E-Probe is actually an Electrical Field Detector. It is sensitive enough to pick up the DC Electrical field of the human body but the sensitivity also proves to be one of the difficulties in using the device. As the device needs to be adjusted constantly to prevent saturation of the circuits.
Overall, for less than $50 it's a solid and reliable investment despite it's quirks.