...
Details:
At first, it's designed to work as a normal SD card for every camera out there, but unfortunately I don't found such a small battery. So it's a little bit bigger than a SD card.
It's got a battery in it with the necessary electronic to charge it every time it's connected to a PC or camera (5V over the USB port).
It has about 28 LEDs in it. 10 blue ones for the shiny ring in the middle, 10 Green one at the connector (the tiny holes) to mimic a functional optical data transfer and 8 LEDs to display the charging status of the battery while connected. These are placed at the 4 hole (2 left and 2 on the right side).
All the electronic is controlled with a Atmel Mega8 microcontroller.
When you disconnect the data chip from a helmet it runs for about 2 hours and does all the fancy bling bling stuff the one from the game does. That was the main goal.
Inside as you can see on the last pic is a tiny PCB which holds all the necessary electronics to charge, light up or transfer the data.
The blue brick is the battery and the big black thing is a 32GB micro SD card.
...