So most of us here are much more familiar with Dangerous Things products, I had a quick look at the i am robot x3 elite, and it appears to be the correct product for you, although the information provided was actually pretty limited and disappointing.
I have no first hand experience with i.a.r. products so I can’t attest to the quality/ reliability etc.
What I can do is just bring to your attention the Dangerous Things equivalent.
xM1 Should do the job for you. (can you confirm if you current card is 4 byte or 7 byte?
That is the same form factor as the X3
The other options you have are
FlexM1gen1a (improved range over the xM1 and X3)
FlexM1gen2 (improved range over the xM1 and X3 plus you can write to it with your phone)
Understandably, What you may be considering is the price difference.
I.a.r. X3 USD$99
DT xM1 USD$120 (ships from USA)
DT xM1 USD$127 (Ships from Europe KSEC)
You might want to save a few dollars, but remember, this is a thing you are going to put inside your body.
I can also tell you, the testing and safety of the Dangerous Things products are exceptional.
It will live far longer than you