It is a type of channel, mostly used in industrial and commercial applications, that allows you to clamp pipes (electrical, plumbing etc.) firmly in place. It comes in 10 and 20 foot lengths. It can be galvanized, powder coated or stainless steel. It can also come with mounting slots every 2" apart. There are many fittings that allow it to be fastened together in many ways, including ladders!

Pic of 2 pieces.