There is one head unit and three separate remote receivers / antenna's, one each at three of the four wheel locations.. The fourth tire is figured out by process of elimination.FWIW, there is only one TPMS receiver that serves all four wheels.. It's located on the rear cross member.
See post 18,19 and 20 in this thread--> https://www.wranglerforum.com/f274/service-tpm-system-2076505.html#post30793313
How a single receiver can tell where each wheel is mounted is beyond me. This TPMS business is probably one of the most confusing aspects of modern vehicles
Off hand I do not have any pictures of what they look like. But this thread has a great description of how the two versions of the system work (the base system is simpler that the four tire readout EVIC system)Any idea on what 3 wheels the remote receivers are at and what they look like?