This black Grace Glass Precooler is a unique smoking accessory for your bong! It is used as an additional precooler for your smoke before the latter enters your bong and ends up in your mouth. So it furthermore smooths your smoke improving your smoking experience on the whole! It is made of a high quality heat proof borosilicate glass, formed in the shape of a scientific tube. You can place your precious herbs on the blue bowl connecting to a percolator through a sure ground of 18.8mm diameter. The clear chillum diffuser bubbles up your smoke, for cooling your toke. The Grace Glass logo features at the front of the chamber. The precooler fits any suitable bong joint of 18.8mm.