I gave up on those flexible goosenecks.
Many years ago, I bought one of these, and it is a great thing to have when it is needed; but I don't regularly use it.
It is by On-Stage Mic stand products (don't know the official name).
It is the angle adaptor only, not the base. It is threaded for 5/8-27, but, I've adapted my entire rig to 3/8-16, incluidng adaptor threads for this thing.
It is in two parts. There is a screw that draws the two sections together. There are gear-like teeth that hold the sections together, firmly, and hold the angle firmly, until you loosen the sections, and cause a change in angles.
They also make a stubby version that doesn't have the longer reach as shown.