Customer may be looking for a meter that supports Class 200 or Class 20 applications.
The ION8650 series supports the following meter socket options:
Class 1/2/10/20 - 9S, 29S, 36S, and 35S
The ION8650 datasheet is availble here: https://www.schneider-electric.us/en/download/document/998-1257683_GMA-US/
The EV55 series supports the following meter socket options:
Class 200 - 2S, 12S, and 16S
Class 20 - 5S, 6S, and 9S
The EV55 datasheet is attached.