California wine jar bottle. Use glass cutter bit to drill one or more holes in side of bottle to allow pressure equalisation, or to get compression or vacuum effects as wished by finger tip blocking holes. Different brands have slightly differing internal diameters. The glass is by definition smooth but best to add a small amount of lubricant such as olive or coconut oil or petroleum jelly. If you luck into an exact fit for your size of penis, the sensations can be agonisingly, tormentingly enjoyable.