B-Line Eaton series Type 3/3R junction boxes, 12" height, 6" length, 12" width, 3R, Hinged cover, RTHC enclosure, Surface mounted, Small single door,

Yes, outdoors is what the RTHC enclosure is built for. It carries a NEMA 3R rating, which covers falling rain, sleet and external ice formation, and it adds a rain hood over the door. Note that 3R is not a washdown or hosedown rating, so if the box will be sprayed directly or sits where water is driven at it under pressure, you want a 4 or 4X enclosure instead.

12 inches high, 12 inches wide and 6 inches deep, which is where the 12126 designation comes from. Surface mounted, with a single small door. Shipping weight is 10 lb, so it is a one-person hang.

The back has embossed thru holes already formed in it, so you mount it straight to the surface with your own fasteners sized to the substrate. No drilling into the enclosure and no separate mounting feet or panel needed. Fasteners are not supplied.

Five knockouts are provided from the factory, so for a simple feed-through pull you may not need to punch anything. If your conduit runs do not land on those knockout locations, you punch the additional openings yourself; the body is 16 gauge carbon steel, which a standard hydraulic knockout punch handles.

There is a padlock provision on the door, so you supply the padlock and the box secures. The cover is hinged on a formed top hinge and is also removable, which helps when you are pulling conductors and want the door out of the way entirely.

The shell is carbon steel with a painted finish in ANSI 61 grey, the standard gear grey most switchgear and industrial panels are finished in, so it matches an existing lineup. Steel enclosures do rely on that paint film for corrosion protection, so in coastal or chemically aggressive locations a stainless or non-metallic enclosure is the better call.

Six inches of depth behind a 12 by 12 opening gives working room for splices, terminal blocks or a small DIN rail on a subpanel, but the RTHC ships as an empty enclosure, so any panel, rail or terminal strip is ordered separately. Remember the hinged door swings into your clearance in front of the box, and the rain hood adds a bit above the top, so allow for both when you pick the mounting spot.

An RTHC style box hangs its door on a formed top hinge with a padlock provision, so it opens with one hand and stays captive when you are working in it, and the cover can still be lifted off if you want it clear. A screw cover box means backing out every screw each time and setting the plate somewhere. If the box gets opened for service, metering or seasonal checks, the hinged cover pays for itself; for a splice you close up once and never touch again, a screw cover is sufficient.