I bought these to use in two situations. One was to place a tracker in my car for security. The second was to bring along on a long distance trip which included a plane trip. They were easy to set up, register, and work perfectly with Apple's find my system.
My car is now tracked, and I can easily find it with my phone if I need to. When I went on holiday, I brought two along and dropped one in my luggage and was able to track it while waiting for it to come down the conveyer after we landed. As well, I was able to keep track of it when it was in the hotel room. On a few occasions, I gave one of the trackers to a member of our party at an amusement park when we split up so we could keep track of their location. They had a phone but it offered us extra peace of mind knowing we could find them if we needed to or their phone was dead. It worked flawlessly.
Half the price of apple airtags and worked just as well.