Stress control card: A funny entertainment games! A best promotion gift!!! Don't underestimate the power and pull of this little card. It is funny, refinement, wearing well, innocuous to environment and human body and easy to use. You will never know how interesting it is unless you tried it. It is also a best promotion gift. You can put advertisement on this small card. Whenever people hold this card they will also pay attention to your advertisement. Now let me told you how it works! Simply hold your thumb on the Stress Control Card indicator for about 5 seconds, until it changes color. Black: Means you are stressed. You had better take a rest or vacation. Red: Means you are tense! Green: Means you are normal Blue: Means you are calm Customer? design is welcome! Any shape is available!!!