This 14mm Female to 18mm Female Glass Dropdow is great for moving the heat away from your nice glass water pipes or dab rigs. Moving the heat away from your pipe is very important especially with dabbing. With this dropdown, you can prevent your glass pipe from suffering heat stress, fractures, or damage. These convenient accessories allow you to turn your change the joint size on your dab rig or bong. *Exact shape of the downstem may vary slightly.