Reentrant presented the following explanation :
Here's the brochure for the module on our meter: http://tiny.cc/9svzfz


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It looks nothing like that - It looks just like a normal meter,
entirely brass on the outside case and rather transmitting to a base, I
understand they drive by to collect the data. I have seen several YW
vans with a very short vertical antenna on them, possibly Ghz
frequency, so I would suspect that may interrogate the meter.