B-Line Eaton auxiliary support channel, Steel, Pre-assembled channel, spacer, and hardware, 10" length, Yellow zinc finish, 2" X 9/16" Support channel

It ships pre-assembled with the channel, spacer, and hardware together, so there is nothing extra to buy to make the assembly itself complete. What it does not include is whatever anchors it to your structure, so the fasteners into concrete, deck, or steel are on you.

The finish is yellow zinc chromate over steel, which is a plated corrosion-resistant coating meant for dry indoor service. For sustained outdoor exposure, wet process areas, or corrosive environments, go with a hot-dip galvanized or stainless channel support instead. Yellow zinc holds up well in mechanical rooms, electrical rooms, and enclosed ceiling spaces.

It's a short pre-made channel-and-spacer assembly used to stand a support off a surface or structural member so you can hang conduit, cable tray, boxes, or fittings clear of the substrate. The spacer sets the offset, the 10 inch channel gives you the run of slot to position your clamps or straps along. It's a made-up subassembly rather than loose strut you cut and shim yourself, which is why it's specified where a repeatable standoff is wanted across many hangers.

Certifications are marked Not Applicable for this steel support channel assembly. It's a structural support component rather than an electrically rated device, so specify it on load and material grounds, not on a listing mark. If your submittal requires a listed support, that requirement typically falls on the raceway or tray system it carries.