This device will help broadcast eletromagnetic energy in the room while investigating.  The theory behind this is that this extra energy will help give any spirits some extra enrgy.   You may get more active EVP session, spirit box session, dowsing rods, rem pods, trigger props, etc.  This device runs silent, so you won't have that buzzing background noise.  This handmade device is small and sleek, allowing for more room in your equipment cases.

One device covers a small to medium-sized room. For larger spaces, you will need more devices to help spread the energy around.
 
The device runs off 2 AA batteries (not included)
On/off switch (batteries don't need to be removed)
Blue LED indicator light (so you know it's working)
 
This is handmade and made to order (all devices will function properly, there is a small chance they may not be perfect visually).
 
They are sold as single units, photos are for demonstration purposes