It WORKS!
I was a skeptic.  I couldn't imagine an electronic device would actually keep the mice away.  We would routinely find two to five mice every morning (we live in very rural Wyoming, so this isn't unusual) in our various traps.  Since connecting the mouse blocker, we have found NONE!  Is it a little pricey?  Yes. But a new wiring harness (which I've had to replace before) costs a whole lot more.  REALLY happy with this purchase!
Rating: 5 stars