Sounds very similar to the Tile I use for the same purpose.If you are worried about finding keys or other things, and you happen to have a newer iPhone, there’s nothing better than AirTags. You hang an AirTag on your keys and when within 50 feet or so the phone will take you to within inches of where the AirTag is. This is simply amazing.
I’m not actually sure what the distance limitation is. They also work if you lose the device that the AirTag is attached to and somebody with an iPhone comes by. The Airtag will communicate with the iPhone of a stranger and give you an indication of where the last place was that it was detected by that person, who you will never ever meet or know who it is. And they won’t know they helped you either.
Just another option. But an AirTag costs $25, and you need a newer iPhone to utilize the precision finding.