To use this mug, simply pour hot or cold liquid into it and watch the design change. The heat - sensitive feature reacts quickly to temperature variations. When it comes to cleaning, remember to only hand wash it. Avoid using abrasive cleaners as they might damage the heat - sensitive design. Keep it in a dry place when not in use. This mug is about 11cm tall and 9cm in diameter, so make sure you have enough space for it in your cabinet.