+++Retread7 and Dakota Alert
We've been using Dakota Alert products for decades. They are the best.
If you're serious about it, go with quality. Harbor Freight's will go off due to direct sunlight, little lizards, and birds. Good only in a pinch.
No dog, not my catahoula or my walkers or the mutt can be as reliable as the dakota alert. spend the money for a li-ion battery, and you'll almost forget about it. plug the receiver into an uninterruptable power supply and you're set for power outages too.
In the land of the blind, the one-eyed man is king. -T.W.