B-Line Eaton series Type 3/3R junction boxes, 12" height, 10" length, 12" width, 3R, Screw cover, RTSC enclosure, Surface mounted, Small single door,

Yes. The Eaton B-Line 121210 RTSC enclosure carries a NEMA Type 3R rating, so it is built for outdoor use against rain, sleet and falling dirt. It ships with a rain hood and plated screws, and the carbon steel body is painted ANSI 61 grey. It is UL 50 listed. Mount it upright on a wall so the hood sheds water as intended.

The 121210 RTSC measures 12 inches high, 12 inches wide and 10 inches deep, which is where the 121210 designation comes from. That 10 inch depth is generous for a junction box and leaves room for splices, terminal blocks or a small DIN rail behind the door. It weighs 13.3 lb, so a single installer can hang it without help.

There are 5 knockouts in the bottom of the box and none elsewhere, which is correct practice for a 3R outdoor enclosure since conduit entries below the level of live parts keep water out. If you need side or top entries you will have to punch them yourself and use raintight fittings to keep the 3R rating intact.

It is a screw cover, not a hinged door. The flanged cover lifts off once the plated screws are backed out, which gives you full open access to the box but means you are handling a loose cover on a ladder. If you need a door that swings and stays attached for frequent access, look at a hinged-cover 3R enclosure instead of the screw-cover RTSC.

It is a surface mount enclosure with embossed thru holes in the back. The embossing stands the hole off the mounting surface so water cannot track into the box at the fastener, which is why you should use those holes rather than drilling new ones. Fasteners are not part of the box, so pick anchors to suit the wall material and the 13.3 lb load.

The body is 16 gauge carbon steel with a painted ANSI 61 grey finish, the standard grey used across industrial electrical gear so it will match panels and disconnects already on the wall. Screws are plated to resist corrosion. For coastal or washdown areas where steel will eventually rust through the paint, a stainless or non-metallic 4X enclosure is the better call.

Yes. A 3R enclosure handles outdoor rain and falling dirt, and that covers ordinary indoor dry locations as well, so the 121210 RTSC is fine in a mechanical room or parking garage. What it is not rated for is hosedown, heavy dust or oil, which call for a 4, 12 or 4X box. Also note the bottom-only knockouts, which can be awkward indoors if your conduit drops from above.

Order Eaton B-Line part number 121210 RTSC. The number reads out as 12 inch height, 12 inch width and 10 inch depth, with RTSC identifying the raintight screw cover style. It is made in the US.