B-Line 121816 Eaton series CT meter socket and enclosure combo, 20 A, Ring type door /cover, Overhead and Underground, ANSI 61 gray painted, #14-#10 load and line lug size, Galvanized steel, 6 jaws, 1 position, CT, NEMA Type 3R

Yes, the 121816 has a 6 jaw, 1 position socket, so it takes a 6-jaw transformer-rated meter in a single meter position. A 4-jaw or 7-jaw meter will not seat in it, and it will not serve two tenants, it is one position only. Confirm with your utility which meter form they will set before you order, because the jaw count has to match their meter.

Plan on a footprint of 42 x 24 x 11 inches for the 121816 enclosure. It weighs 100 lb, so this is a two-person lift onto the unistrut or backboard, and the wall needs to carry that load plus the conductors. It is a surface mount unit, so all 11 inches of depth stand off the wall.

Either one. The 121816 is built for overhead and underground feed, so the same unit works on a pole-fed service drop or a lateral coming up from a trench. That matters on a retrofit where the utility is converting the service, because you are not buying a different can when the feed direction changes.

It is a CT type unit, a combination CT cabinet and meter socket in one enclosure, not a self-contained socket. The current transformers carry the service current and the meter reads their secondary output, which is why the meter side is rated 20 A and the lug size is #14-#10: those lugs land small CT secondary and control conductors, not the service entrance conductors. If you are looking for a socket where the service conductors land directly on the jaws, this is the wrong type.

It includes a removable test switch perch, so there is a factory provision inside the enclosure to mount the utility's test switch block without drilling the can. The perch comes out if the utility does not use one. Note the test switch itself is not part of the unit, the mounting provision is.

The lugs take #14 through #10 conductors on both line and load. That range covers CT secondary leads and metering control wiring. If you are trying to land #2, 4/0, or larger service conductors, they do not go on these lugs, they terminate on the CT primary side in the cabinet section.

The part number is 121816, from the Eaton B-Line series. That single number covers the whole configuration: CT meter socket and enclosure combo, 20 A, ring type cover, 6 jaw single position, galvanized steel in ANSI 61 gray, NEMA 3R, for overhead or underground feed. There are no finish or size options to specify, it is ordered as one model.