This is a pre-assembled board that is available on our Tindie store. It's a surface-mount version of our I Voted/Yo Vote Blinky Badge Solder Kit. Or, if you have parts and would prefer to make it yourself, you can order the boards off of OSHPark (in purple, of course!). A bill of materials is in the files section below.
The board uses a transistor-based astable multivibrator circuit to make the red and blue LEDs alternately blink. We'll update the Project Logs section with a description of the circuit and how it works soon.