You can still buy it. I found mine. The two tags are not NTAG 424 though. Which means they are not compatible with the bolt card implementation. I did try to setup a DIY LNBits Bolt implementation with my bolt card tonight though. I was getting a key error. I probably need to expose another URL to my server. I'll get it working another time. For now, I wrote my LN address on one tag and my Nostr address on the other tag on the NFC Ring. 🤙🏻