For pipe wiring, when encountering nodes or turning corners in the wall, the middle branch pipe is a male/female/external threaded fitting that can be connected to external parts, and the two ends are...
Used for pipe wiring, nodes or corners in the wall when turning, connecting / docking the middle branch pipe and the two ends of the size of the pipe with a different nominal diameter.
Used for pipe wiring, nodes or corners in the wall when turning, the intermediate branch pipe can be connected to the external components of the internal thread / internal wire / internal threaded fit...
