The issue about compressed air manifolds is that if you don't know about them at all, you may be having some difficulty in plumbing your compressed air that they would provide the solution for. Yet, if you don't know about them, you can't use them, can you? This page provides in depth information about compressed air manifolds.
The image is of a basic air manifold. This one appears to be made of aluminum.
In the image you can see there is a threaded port on the top, two on the side facing you, and if you look down inside the bottom port, you can see that there is another threaded port on the bottom, as well.
Bring a supply of air to any of these ports, and you now have multiple ports to plumb that supply of air to many locations.
Manifolds can be manufactured by machining metal or plastics, and are made by the casting process as well. Materials include specialty plastics, aluminum, steel, and white-type casting metals.
Some are manufactured specifically for one application, but most of them are similar in concept to the one above.
In the photo above the compressed air manifold shown is a 2-station, dual air manifold.
The user would bring an air supply to the thread on the end, and then install quick connects for fittings in the ports along the side of the compressed air manifold. In this way, one supply would then be able to send air to multiple applications.
This particular manifold is a bit different than the norm. Not only does it have a supply port on either end (you cannot see the one on the other end) like many air manifolds do, this one is blocked mid way, so that an air supply with one pressure could be plumbed to one end, and a different air supply (or maybe vacuum?) could be plumbed to the other end. Each end of the manifold supplies only part of the ports on the side.
The Norgren compressed air manifold pictured above is a bit different than others shown on this page. This one contains instant fittings already installed in the air line ports so all a user has to do is mount this manifold and insert polyethylene tubing in the various fittings to supply various parts of a machine with compressed air. Even what would normally be a supply port on the left end of this manifold has been converted into an instant fitting for the users convenience.
If you require a unique compressed air manifold, or one made of a specialty material (stainless steel, for example) your best bet is to contact one of the major industrial penumatic supply companies, of which there are many. Search in your browser for Norgren, Numatics or SMC to name just a few, or if you just browse for air manifolds you will find many.