Thicker, .030 laminated plastic Mood Cards and Stress Cards! Higher perceived value. Design your own (mood or stress card) for that up-coming event. No difference in price or production time. If being used as a custom designed stress testing card, Although the Stress Card with a liquid crystal tab is a promotional product, there is validity to it. It is designed to be used at room temperature (70 – 74 degrees) and by people who do not have circulatory issues. The crystal is set to activate to different levels (colors) at specific temperatures. The crystal measures the body temperature. When relaxed, the blood vessels are at the extremities (fingertips, nose and toes), which makes those areas warmer. When anxious or stress, the blood vessels move inward, making those areas cooler. The Stress Card is not just a stress test. It is also a stress control device. What color you register initially is not as significant as the fact that you can change the color by going through one of the highly effective quick relaxation techniques on the back of the card. Not only is the stress card used in the Health Care Industry, but it's also been used to teach Biofeedback to pilot training FAA training, Navy and Airforce, Alcohol and Drug Rehabilitation, Mental Health, Cigarette Smoking Rehabilitation, etc.