@Anne1962 Hopefully sorted now. These are smart Tags with a bit of memory , small enough to integtrate into a variety of products.
Anyone interested can see a bit more here: https://electronics.howstuffworks.com/nfc-tag.htm
I do not work for Samsung or make Samsung Products but provide independent advice and valuable contributions.
My Device- S21 Ultra 5G ( SM-998B/DS ) CSC= BTU , 12GB/256GB
One Ui 5.0,Android 13 .