The AirTags are priced at $29 for one or $99 for four. If you want to attach them to something, such as a key ring, you’ll need to buy an accessory. There’s the Belkin Secure Holder with Strap for $12.95, or if money has no meaning to you, the Apple...
https://www.techspot.com/news/89521-ifixit-shows-you-can-add-key-ring-hole.html?utm_source=dlvr.it&utm_medium=blogger
https://www.techspot.com/news/89521-ifixit-shows-you-can-add-key-ring-hole.html?utm_source=dlvr.it&utm_medium=blogger