This pair of Shape 19mm Aluminum Rods (10") connect into your camera rig, extend it, and let you add various Shape and third-party accessories compatible with 19mm rods. With these two rods and with a few fundamental accessories, you can most certainly even begin building your own rig from scratch.
The rods are each 19mm in diameter, 10 inches long, hollow, non-threaded, and made of reliable aluminum coated with a clear finish.