This has at least two metres of extension cable. I've left some kind of gizmo on it - but I've no idea what it is, all I know is we used it, but you can remove it if not needed. The phone line pops into the shuttered opening. The other opening looks like ethernet but we didn't use it so I don't know what it's for.
We don't need it any more as we have got rid of our landline.
I don't have a smartphone so may not reply immediately.