B-Line B261-12SS6 Eaton series strut fittings and accessories, 10.12" Height, 12" Length, 1.62" Width, 1.65lbs, Steel, Corner to brace length 10-1/8, Two hole knee brace, 45 deg, Load capacity 1020 lbs, Stainless steel type 316

Yes. It's stainless steel type 316, which is the grade specified for coastal, wash-down, water treatment, and chemical exposure where plain or electro-galvanized fittings corrode. For dry indoor runs a plain or pre-galvanized brace does the same mechanical job for less, so the 316 version is worth specifying only where the environment demands it.

The brace measures 10.12 x 12 x 1.62 inches, and the corner to brace length is 10-1/8 inches. That 10-1/8 figure is the one to check against your layout: it's how far along each leg the brace lands from the corner, so you need clear channel for that distance on both the horizontal and vertical member before the next fitting, conduit clamp or pipe hanger. It weighs 1.65 lb.

The B261-12SS6 is a two hole knee brace set at 45 degrees. It ties a horizontal strut run back to a vertical member to triangulate the corner, so the joint resists sag and racking instead of relying on the channel nuts alone. It's a support bracing piece for strut framing on electrical and mechanical work, not a hanger or a beam clamp.

The B261-12SS6 is the brace only. It has two holes, one at each end, so you need two fasteners plus matching channel nuts sized to your strut to hang it. Order those separately, and in a 316 stainless application order the hardware in 316 as well, otherwise the fasteners corrode before the brace does.