Effect: 

 The magician states that his heart has the rare ability to predict a card that will be chosen, and that the predicted card will show up on his forearm, which he shows to be currently without any sign of such. The spectator chooses a card from the magician's deck.

 The magician's forearm then is made fully visible without any visible prediction. Suddenly his forearm muscles begin to move, which seem to force his veins to begin flowing "blood red." The bright red blood travels until it reaches just below his elbow on the forearm, where the chosen card suddenly shows at the end of the blood flow, and amazingly, that card's number and suit are revealed, just as predicted!

 Countless effects are possible!

 Important points:

 You can start clean and end clean. Everything is concealed in very little space!

UV LED with low visible spectrum emission.

Includes a pen that contains a high quality red invisible ink.

Includes a pen that contains a high quality blue invisible ink.

Hi-tech rechargeable micro-battery. Lithium-polymer based.

Includes a battery charger.

The inner UV mechanism of the gimmick can be taken out easily and be put in many other places if needed.