B-Line U217 MTBH Eaton series meter breakers, 100 A, Test block, Ring type, 3R, ANSI 61 gray painted, 010kIAC, #14-2/0, #14-2/0, Steel, Surface mount, 7 jaws, 3 poles, 3Ø/4W

Three phase. The U217 MTBH is built for 3-phase, 4-wire service with a 7-jaw meter socket and a 3-pole, 100 A main breaker. If your service is single phase 120/240V, this is the wrong socket configuration, you need a 4-jaw, 2-pole unit instead.

Yes. The U217 MTBH is a Type 3R enclosure, rain-tight for outdoor surface mounting, and it is surface mount rather than flush or semi-flush. The shell is galvanized steel finished in ANSI 61 gray paint, which is the standard utility gray for exterior service equipment.

Both the line and load terminations accept #14 through 2/0 conductors. That covers a 100 A service run in 2/0 aluminum or 1/0 copper, which is the usual pairing at this rating. If your service entrance conductors are larger than 2/0, they will not land in these lugs.

The U217 MTBH is EUSERC Approved and UL listed, which is what most western US utilities require before they will set a meter on new service equipment. Utilities still publish their own approved equipment list, so the ring type socket and test block arrangement should be matched to what your serving utility specifies for the meter position.

It is a combination unit. The meter socket and the 100 A, 3-pole main breaker are in the one 3R enclosure, so it serves as the service disconnect for a 3-phase, 4-wire service and no separate outdoor disconnect is needed. Branch distribution still has to be fed from it to a downstream panel.

Plan for 24 inches high by 18 inches wide, with a 4.625 inch depth off the wall. It weighs 38 lb, so one person can set it, though a second hand helps holding it plumb while the mounting fasteners go in.

The test block lets the utility test or bypass the meter without pulling the service conductors, so meter changes and verification happen without an outage on the load side. Ring type means the meter is retained by a sealing ring at the socket rim, which is the more common utility requirement of the two. If your utility specifies ringless, their cover style will not match this unit.

Order Eaton B-Line U217 MTBH. That designation covers the 100 A, 7-jaw, 3-pole, 3-phase 4-wire ring type meter breaker in the 3R gray painted steel enclosure, so repeat orders land the same configuration every time.