biofeedback cards

Stress biofeedback card, we also call stress control card. It can be used as Sex tester card, Lover card,
Usage:
Hold your thumb onto the Stress Control Card indicator for about 15 seconds, until it changes color.
Blue - you're calm, Green - you're normal
Red - you're tense, Black - you need a vacation!
Detail:
We can offer the regular size, or we can produce according your specific designs. It is made as durable plastic temperature indicator. A liquid crystal square changes color when the finger warmed it, indicating Stressed, Tense, Normal or Calm, warms it.