These gas line splitters are sold in single 'sets' enabling you to keep adding on to make as many outputs as you like.
Image shows 2 'sets' connected together
They are easy to use and assemble and made from high strength food grade plastic.
The come with Brass connectors.
In each set you get
Simply buy another set to make a double manifold, or connect as many as you like.
These are made in China...they are not John Guest however similar push to connect style.