It uses a 555 timer to alternately flash each set of 9 LEDs, for 18 blinking LEDs of goodness.
Step 1: Parts
4 AA Battery holder
PNP Transistor (3906)
NPN Transistor (2222)
2 x 3./4" Quick relase
12" of webbing
2 x molex KK connectors
thread and needle
Step 2: Cut Out the Straps
Sew it together so it will nto come out of the quick release
Step 3: Build and Test Your Circuit
Step 4: Solder It Up.
Here I used two molex KK connectors, one for each set of LEDs.
Step 5: Time for the Flaps
Then cut 2 18" lengths of wire. Strip enough off of the end to cover all of the LED negative pins and then solder them each to the wire.
Do the same for the positive side.
Here solder on the female molex KK connector and the snap it on to your breadboard.
Do the same for each side.
Step 6: You Done.
You can see in the other pics how it fits in the bag.