This would be good for bicycles (ie an airtag that doesn't look like an airtag)

Bicycle thieves know to look for and remove airtags now, I would definitely pay good money for something more covert, that looked like it was just a part of the bike.

Doesn’t the AirTag start making beeping sounds to alert someone they’re being tracked because Apple doesn’t want it to be used by stalkers? Even if a third-party makes a tag which is silent, would the thief’s iPhone notify them there’s an unknown tracker moving with them? It would defeat the whole point of using them on bikes, etc to catch thieves and recover stolen goods.