B-Line Eaton series wiring trough, 6" height, 120" length, 6" width, HS wireway, Thru holes, 39 top knockouts, 39 bottom knockouts, Hinged cover, 1,

No. The 66120 HS trough is a NEMA 1 enclosure, which is general purpose indoor protection only. Use it in dry indoor electrical rooms, shops and mechanical spaces. For outdoor, damp or hosedown locations you need a NEMA 3R or NEMA 4 rated trough instead.

The HS in 66120 HS means hinged screw cover. The cover swings open on the hinge so you keep hold of it while pulling and dressing conductors, then it is secured to the body with plated screws. A plain screw cover comes fully off, which is fine for a one time pull but awkward overhead or in a panel gutter you re-enter often. If you expect to open the trough repeatedly, the hinged version is the one to buy.

Knockouts are already there: 39 on the top and 39 on the bottom of the 120 inch body. That gives you spaced entries the length of the run for conduit stubs into panels, disconnects and gutters below. Sides and ends you cut or punch yourself if you need them.

The 66120 HS trough is built to CSA C22.2, so it carries the Canadian standard an inspector looks for on a metallic wireway. It is steel bodied, NEMA 1, for indoor dry locations.

A 6 by 6 inch trough works as a pull and splice gutter for typical branch and feeder work, and the 39 top and bottom knockouts line up entries into gear mounted above or below it. Where you are running large feeders, the 6 by 6 cross section fills fast, so step up to an 8 by 8 or 12 by 12 trough to keep your fill and bending space legal.

The trough itself is just the 120 inch body and hinged cover. Connectors, end plates, elbows, tees and hanger hardware are separate items in the same 6 by 6 HS wireway line, so pick the fittings to match the 6 by 6 size before the run goes up.

Yes, 16 gauge is the standard body thickness for commercial and industrial steel wireway and takes the handling of a working plant. It ships in ANSI 61 gray, the usual gear finish, so it matches panelboards and switchgear already on the wall without repainting.