Reddit:

My wallet was a Gucci branded wallet with about $100 in cash in it and a couple of credit cards, along with my license. I also had enough space in it to stick an Airtag in there (there’s a compartment where it fit easily). I’d initially bought the Airtag as I always lose my things around the house, wallet included.

Anyway, I realized at the end of my workout, about an hour/hour and a half later, that I didn’t have my wallet.

Interesting anecdote about AirTags and Find My.