The REM Pod uses a mini telescopic antenna to radiate an independent electromagnetic field around the device.  It is believed that a spirit can manipulate, distort, and influence energy in an electromagnetic field.  The REM device has 4 LED lights detecting how close the energy is to the antenna when it interrupts the field the Pod is emitting.  The antenna can be extended or retracted to change the sensitivity of the device.

 

We also have a V-Pod that works on the same basic principal.