The Empire Glassworks Sunshine Shrooms Carb Cap is made to fit most quartz and titanium banger nails. Handmade in the USA with American glass rods. Features a UV reactive and glow in the dark martian design. These caps give you directional airflow while you are dabbing that helps ensure that you get the most efficiency with your concentrates and they get completely vaporized. Diameter measures 30mm wide.