Carb hole stopper made of silicone of the brand Heisenberg. The diameter of the plug ranges from approx. 9 to 15 mm with a total length of 26 mm. Thus, the plug fits in most carb holes of commercial glass pipes. The plug is intended to seal the carb hole watertight when cleaning a bong. So you can safely shake them without spraying detergent solution when you want to remove tenacious dirt stains.
