This is a breakout cable that connects all of the PWM outputs of the Storm LED Controller to pre-tinned leads. Just plug in the 2x6 header to the PWM pins of your Storm and connect the other ends to your PWM drivers. You'll notice that there are two wire bundles, one for the top row of pins (PWM) and one for the bottom row (GND). The leads are individually color coded for clarity.
You can also use this cable with the Storm X. The headers do stack side-by-side so with two of them you can address 12 channels, etc.