The 12-pin circular connector used on the power sensors is an Amphenol.? The old part number was 91-T-3638.
Now, it's part of their "C 091 A/B/D" series circular connectors.? Several variations are listed in the Amphenol catalog:


Mouser has several slightly expensive options (a few of which appear in this link -- note that widening the Mouser search filter will supply more results):


It appears that an eBay seller is selling them at a lower price.? His text says they are the 12-pin versions, although his photo shows the 14-pin version.? It's hard to tell which of the two connectors he is selling.? However, it appears the two additional pins shouldn't matter since it's the female part of the connector -- you would leave those two extra pins unconnected.