B-Line Eaton series wireway, 6" height, 36" length, 6" width, 12LW wireway, Wireway hanger, Hinged cover, 12, Steel, Oil-resistant gasket, Hinged, AN

It's a NEMA 12 wireway, which means it's built for indoor use against dust, dripping non-corrosive liquids and falling dirt. The oil-resistant gasket under the hinged cover is what makes that rating work, so machine shops, plant floors and areas with coolant or oil mist are the intended use. NEMA 12 is not a wet-location or outdoor rating, so if the run is exposed to rain or hose-down, you need a NEMA 3R or 4 wireway instead.

14 gauge steel, finished in ANSI 61 gray. That's the standard gray used across most industrial control gear, so it'll match adjacent panels and enclosures on a plant floor without a repaint. 14 gauge is the heavier end of wireway construction, which is what lets the trough span between hangers without oil-canning.

The 6636-12LW is certified to CSA C22.2, so it's acceptable for Canadian installations under that standard. Worth confirming with your inspector which specific C22.2 part governs your enclosure application on the drawing.

Only if the dimensions line up. A NEMA 1 screw-cover 6x6 and this NEMA 12 6x6 share the same 6 in by 6 in trough size, so the physical run and fittings correspond, but NEMA 1 is a general-purpose indoor enclosure with no gasket. Going the other direction, replacing a NEMA 12 section with NEMA 1 breaks the dust and drip protection for the whole run, since the rating is only as good as the weakest section and joint.