B-Line Eaton series wireway, 4" height, 18" length, 4" width, G NK wireway, Thru holes, No knockouts, Screw cover, 1, Steel, Plated screws, ANSI 61 g

No knockouts. The NK in 4418 G NK means exactly that, so every conduit entry gets field-punched where you want it. In 16 gauge steel a standard knockout punch handles it without trouble. If you'd rather not punch, you want a knockout-style wireway instead of the NK version.

NEMA 1 only, which is general purpose indoor. Screw cover, steel body, no gasketing called out. Do not run it outdoors, in washdown areas, or anywhere it can take dripping water or dust loading. For those you need a NEMA 3R or NEMA 4 raintight or oiltight wireway instead.

The cover is a screw cover, held by plated screws along the flange. You take the screws out to open it, so it's fully reenterable for pulling or re-landing conductors, but it isn't a hinged or latching lift-off. Plan on a nut driver and somewhere to keep the screws if the section is overhead.

Mounting is through holes in the body, so it bolts or screws straight to a wall, backboard, or strut with your own hardware. Fasteners and struts aren't part of the section, so order those separately. At 18 inches you generally want support at both ends rather than cantilevering it off one point.

It's the same Eaton B-Line 4 x 4 G series screw cover trough in ANSI 61 gray, so it lines up in color and profile with other 4 x 4 G sections already on the wall. The one thing to check is that your existing run is also the screw cover G type and not a hinged cover line, and that you have the connectors and end plates on hand, since those are separate items from the trough section.

It carries CSA certification. Steel construction, 16 gauge, NEMA 1 general purpose enclosure. That's the certification held on record for this trough; specify to your drawing if the spec calls for a different listing.

16 gauge steel is the standard body weight for 4 x 4 general purpose trough, and it holds its shape when you're punching entries and pulling conductors through. The ANSI 61 gray finish is the usual gray electrical equipment color, so it sits alongside panelboards and disconnects without standing out. For indoor industrial and MRO use it's the normal choice; it's the NEMA 1 rating, not the gauge, that keeps it out of wet locations.