This Bubble Style Carb Cap is made to fit most quartz and titanium banger nails. Made with borosilicate glass and shaped like a tortoise. Bubble style caps provide directional airflow while you are dabbing. Being able to direct the airflow helps ensure that you get the most efficiency with your concentrates and they get completely vaporized. Diameter measures 26mm wide. Come in assorted colors which may vary from pictured.