Well, when I looked inside the Arduino packaging, I noticed 4 doted lines.
I Have cut the packaging along this doted lines, and Voila:
This is the Arduino Ethernet Version, I don't know about the other Arduino Packagings.
WATCH IT !!!, I DIDN'T TEST HEAT EMISSION BY THE ARDUINO. => Autoignition point paper: 218°-246°C (424-474°F)