This 2 piece screw & marble terp bead set includes a large marble carb cap and a screw style flow bead that is perfect for use with the Terp Slurp Banger. Terp beads assist by stirring concentrates via airflow and regulating airflow as a marble cap. Multiple colour options available. Marble set approximate sizes are 23.75mm marble diameter & 26mm x 14mm screw dimensions. Please Note that the terp slurper bangers are sold separately and are shown for illustration purposes only.