That attachment loop costs more per unit than the dual-protocol tags themselves that another commentator mentioned.

I use quite a few varieties, including Apple's, and I have found Belkin’s to be an ideal one — small, secure, with a minimal footprint, and available with a keyring or a lanyard.

https://www.belkin.com/p/secure-holder-with-key-ring-for-air...

Dude... not cool to put your Amazon `ref` link in there....