B-Line Eaton series wireway elbow fitting, Lay-in, 90° elbow, side opening, 1 rating, Steel, ANSI 61 gray painted, 12" X 12"

Yes. The 1212 FL SIDE is built for 12 inch by 12 inch lay-in wireway, with a stated height of 12 in and length/depth of 12 in. It turns the run 90 degrees with the opening on the side, so it mates to the ends of standard 12 x 12 trough sections. If your run is a different cross section (6 x 6, 8 x 8), you need the elbow sized to that trough, not this one.

No. It carries a NEMA 1 degree of protection, which is indoor, general purpose, dust and falling dirt only. For a rooftop, a wash-down area, or anywhere exposed to water, you need NEMA 3R or NEMA 4 gasketed wireway and fittings. Putting a NEMA 1 elbow in an outdoor run will fail inspection.

It is about which plane the turn happens in. The 1212 FL SIDE takes the run around a corner horizontally, with the removable cover on the side face so you can lay conductors in from the side. If your run has to change elevation (go up a wall or drop down), you want the flat/top opening version of the elbow instead, where the access cover faces the same direction as the wireway covers on a horizontal run. Ordering the wrong orientation means the cover ends up facing a wall or the ceiling and the run is no longer lay-in accessible.

That is the point of it. The lay-in design means the cover comes off and conductors drop straight into the fitting, so you are laying wire around the 90 degree turn instead of pulling it blind through a conduit ell. On long feeder runs with large conductors this is why wireway gets specified over conduit in the first place.

The elbow is painted ANSI 61 gray, the standard gray used across Eaton B-Line series wireway and on most switchgear and panel enclosures, so it matches existing B-Line trough and typical gear in the same finish. Body is steel, so it can be touched up or field painted if you are matching a non-standard color.

It weighs 17.096 lb, so a single installer can handle it, but at 16.31 in across one dimension it is bulky enough that you will want it supported or temporarily strapped to the trough while you land the connecting hardware overhead.