It’s just a xEM. It’s actually met my LF keyfob reader already, which I brought along with my cellphone and an OTG cable to check that it reads correctly - or more accurately, that it stayed behind in my foot after the needle was pulled out. I’ve had chips coming back out with the needle, even with the plunger fully depressed, sticking to the end of the needle by capillarity with the blood.
It reads from the top with the keyfob reader alright, but not from the bottom. That was to be expected. This evening I’ll see if it rings with my long-range reader from the bottom.