B-Line Eaton series runway retaining post, Used to increase cable capacity fill of runway, Cable retaining post, A513 steel, Yellow zinc

The SB117A2YZ is a 15 inch tall retaining post that bolts to a cable runway stringer to raise the effective side height, so you can stack more cable in the runway without it spilling over the edge. It is a capacity and containment part, not a support part, so it does not change the runway's load rating or replace runway supports.

Each post stands 15 inches tall, so that is the added side height available for cable fill above the stringer. The footprint is small, 1.5 inches deep by 1.3125 inches wide, so posts go in at intervals along both stringers rather than continuously. Spacing is driven by your cable bundle stiffness and the runway's own splice and support points; posts are ordered individually and each one covers a single point on the stringer.

Yellow zinc plated A513 steel is an indoor, dry-location finish, which is where cable runway retaining posts normally live: MDF, IDF and equipment rooms. For outdoor, damp or corrosive environments you want a hot dip galvanized or stainless runway accessory instead, since zinc plating is a thin sacrificial coating.

Posts are the retrofit answer: the runway is already installed and full, and you need more fill height without pulling cable out or re-hanging steel. At 15 inches they add a lot of side height cheaply. If you are designing new and already know the final cable volume, a taller stringer runway or a second tier of runway is the cleaner build, because the runway side is continuous rather than a set of discrete posts.

Order it as Eaton B-Line SB117A2YZ. That designation covers the 15 inch cable retaining post in yellow zinc A513 steel; the trailing YZ is the finish, so do not substitute a plain or galvanized suffix if your job is finish-matched to existing yellow zinc runway accessories.