From the Manufacturer The Ghost Meter has been calibrated to ignore the extremely subtle EMF emissions surrounding the human body, yet is still sensitive enough to detect the small, distinct, erratic EMF energy fluctuations frequently found at reputed haunted locations. The Ghost Meter provides three corroborating indicators of EMF emission strength. A needle based display, LED lights, and an adjustable audio signal. The response time of this meter is excellent, easily outperforming more expensive EMF meters. It can also be operated in silent mode so it doesn't interfere with EVP (Electronic Voice Phenomenon) recordings or distract other investigators during an investigation. Compare the value this meter offers compared to other brands. There is no other offer that comes close to providing these levels of features and performance for the price. You've seen television ghost hunters use similar detectors. Now you can get your own and start investigating the unknown. Please note: this product is intended to measure electric fields, and does not detect nuclear radiation.