This is the Solid Valve, the heart of the Solid Valve Vaporization System for Volcano vaporizers.
This Solid Valve has two clips on the side and it attaches to your chamber while you are pumping your balloon. When your bag is filled you click it off the chamber and place it onto the mouthpiece.
Comes in one piece, however, it is very modular and comes apart by unscrewing the stainless steel cap at the end of the steel tube insert.
They last for a long time unless the clips on the side break off. It happened to me once while I was cleaning it in hot water, and have been a little more gentle with my new valve ever since.
All parts of this product are food grade and made in Germany by Storz & Bickel.