OrigamiUSA just listed this model available for download purchase. I love it! Once the paper is cut to the correct ratio (proportion) the units are very simple to fold and assemble. There are 12 units total. Each unit is 1:√2 (sized down from 6" square). I folded the model from inexpensive kami.
You can purchase the diagram here.
Below is a very dramatic-sounding demonstration video.
