B-Line Eaton series strut fittings and accessories, 3.5" Height, 6" Length, 6" Width, 3.92lbs, Aluminium, Square post base, centered offset, Fits chan

The B280AL square post base is made for B22 channel. B22 is the deeper double-channel profile, so if the post you are setting is single-height B22-width strut this base is not the match. Confirm the channel stamp on the strut before you order.

The plate footprint is 6 by 6 inches and the fitting stands 3.5 inches high. Allow that 6 inch square of clear floor or pad around the post location, and add the 3.5 inches to your strut cut length when you are figuring finished height to the top of the frame.

No. The B280AL is the fitting alone, 3.92 pounds of aluminum base. Concrete anchors, the channel nuts and the bolts that tie the strut into the base all get ordered separately, sized to your channel and your substrate.

On the B280AL, centered offset means the strut post lands centered on the square base plate rather than flush to one edge. That matters when you are laying out anchor holes from a column line or a dimensioned point on the slab, since the post centerline sits over the middle of the plate footprint.

The B280AL is solid aluminum, body and finish both. Aluminum won't rust the way a plain or electro-galvanized steel fitting will, which is why it gets used on rooftop and exterior equipment supports. Pair it with stainless or aluminum anchors and hardware so you are not setting up a dissimilar metal problem at the plate.

That's the usual application. A square aluminum base with a centered post keeps the load over the middle of the plate, which is what you want under a freestanding rooftop stand or an equipment frame rather than a wall-mounted bracket. The catch is channel size: it takes B22 strut, so a frame built from a different profile needs the matching base for that profile instead.