Black Leaf Revolver Cylinder Oil BongCute but very robust and stable BLACK LEAF oil rig in the shape of a revolver cylinder. The small bubbler made of borosilicate glass is equipped with an oil nail and dome. The inline diffuser cools down the potent smoke a little bit. It's that easy: Put the nail into the bong, heat the pan with a gas burner, let it cool down briefly, put oil on the pan with the appropriate tool. Then put the dome on to provide for a stronger smoke development and