Low-cost tracking device

I am a convert to Apple AirTags. I hide these tiny buttons in my luggage to keep track of where it is. On a recent walk in England our luggage was forwarded each day, and with the AirTag I could track their whereabouts. If I stray too far from my daypack (as if I had forgotten it) I get an alert on my phone. And attached as a fob on our car key, I can track where in the house the keys were left using my phone. I have a friend who slips one in critical packages he ships. I am putting one in all my bicycles. Each AirTag is $29, and its replaceable battery lasts about a year. — KK