Cleaners & Cleaning Supplies - Obsidian Pipe Stem Oil 18ml ROTHNH I'be been using this stuff since it was first introduced. I have dozens of vulcanite stemmed pipes. Once cleaned and oxidation is was removed, Obsidian Oil has kept all my rubber stems protected and shiny will just a an occasional, simple and quick application. It's a small bottle but I'm still less have used only about 1/4 of the contents so far. Good stuff and worth every cent.