These smooth marble looking glass balls, are specifically designed to cool the smoke in your bong equaling a much smoother taste. "How?" you may ask. Through the magic of science of course! The glass marbles are poured gently down into the base of your bong, and capped with water to your preferred level. Once you begin to smoke, the bubbles will emerge from the downstem and immediately get squished together and broke, resulting in a much smaller bubble of smoke. This in turn allows for more surface area of water touch the smoke itself, which results in a cooling effect on the smoke. This effect will be most noticeable when the smoke fully reaches your lungs, you will notice a significant change in harshness and temperature of the smoke. 

Each stone is approx .5 inches in diameter.