We bought a rural property a year ago, erecting a pole barn on a cement slab for RV and other vehicles. Shortly after moving in we found evidence of mice in the poor cabin and in the new pole barn. We sealed the bottom of the pole barn and laid traps there catching quite a few critters out there, in the cabin we did the same. I installed 3 Pest Reject devices in the pole barn, and the fourth in the cabin next to the sink. No evidence of rodents since May 2019.
Important to deny entry, then the devices sound appears to discourage new residences.
We are happy with the "Blue Light" devices and recommend.
Bottom Line: Yes, I would recommend this to a friend