We have one on our dog as a precaution and because we got a 4 pack and it was an extra. So why not. It is annoying thought that even though my wife and I are in the “family” I can’t share tags with her. We swap cars all the time and we have air tags on the keys. Both registered under my account but items we both use regularly and I’m sure many others out there do a similar set up. I wish they just added the convenience of having tags be shared with family already.