These are "Aussie Style" glass bongs from Agung. This means they have a metal stem and cone piece and fit into the bong with the use of a rubber grommet.
These are traditional types of bongs that became standardized in Australia decades ago. The stem type is commonly called "Bonza" which is the Agung standard metal stem that is 15mm in diameter.
Cone pieces are usually made from brass (hence the nick-name brassy).
Agung Aussie style bongs come in a wide range of sizes, shapes and designs.
