This wouldn't apply as much to cat, but for owners of more active dogs...you might want to use a sturdier ring to attach the id tag to the collar. The simple ones that come with the tags don't last long on our dog. I used a small (yet thicker metal) key ring to attach hid id to his collar. Its been on him for at least a year now! Considering that we used to have a heard time keeping his rabies tag attached for just a couple of months, that is a huge improvement!