This 18mm Female to 18mm Female Glass Dropdown 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 18mm male glass pipe into a 18mm female. *Exact shape of the downstem may vary slightly.