Channel Caps are the dream child of Change Glassworks and one of the oldest E-Nail companies Dnail. They revolutionized the carb cap with their coin design that restricts and controls airflow through small specialized cuts on the flat disk. This creates a cyclone effect inside the banger that will spin your terp pearls and concentrate allowing for better overall function. The 38mm Boro coin is the best size for standard 24mm bangers and comes in a variation of colors. These are double sided so each side can be used on the banger. Each style of cut is unique but all produce the spinning effect desired. If you have any questions feel free to reach out to our contact page.