Tony Stark's Arc Reactor

Super simple, two part, low profile arc reactor made as an under the shirt Halloween costume.
Shows clearly through a black thermal and only gets better as it gets dark out.
Here is what you need:
1 battery pack (6V 4x AA)
24 LEDs
4 3x8mm bolts (glue or tape would also work)
1 strap (I cut a road bike tire in half for this)
Tony Stark style facial hair
A pocket for the battery pack