Adapters are specially made glass pieces that will allow you to fit different size bowls to your bong. They come in many shapes and sizes that will fit any bong, bubbler, or rig. The most common sizing for adapters is 14mm to 19mm. An 18mm adapter will fit nicely with a 19mm bowl. These two sizes are often considered the same and used interchangeably. A 14mm to 19mm adapter will pretty much cover every possible combination of bowl, downstem, or ashcatcher possible. Be sure to look at your glass piece and pick the appropriate adapter for your needs. Shop our full collection of quality wholesale glass adapters below.