Gift Pro &reg; Creative Stylish Desktop Droplet Storm Glass Crafts Weather Storm Forecast Predictor Bottle Barometer (Middle, Yellow) The appearance of the liquid transforming from clear to cloudy to crystal flakes predict whether the weather will be clear, cloudy, or filled with thunderstorms. Unique and unusual gift:The cool new and modern Storm Glass is a natural way to forecast the weather. The sealed glass container holds a mixture of distilled water, and camphor that changes in appearance based on forthcoming weather conditions. Note : the Storm Glass may need one or two weeks for the crystal to stabilize and adapt to the environment. If you want to see the test result, can be placed in the refrigerator frozen half an hour to an hour, take a look at the change effect. Material: Glass Package: 1 Pack