When I asked for a new telephone line to be installed, I had no idea that in a few years, that I would be using a modem or a router. Its location was convenient when first installed but too far from the PC for the standard router lead to be of much use. This filled the gap.
It works as well as the original.
However, both my current and previous ISPs were able to detect that I was not using the cable supplied with their routers and that, unless I used the precise equipment supplied by them, I would not benefit from their support services.
It is relatively inexpensive and worth buying if you need a longer length.