So it only contains these black regions, our thin filament, and it extends over two sarcommirs and not over a single sarcomere as our h zone does and the A band does. So now let's move on to our egg band. So the A band actually contains all of our thick filament. So basically, beginning on this side of the filament and ending on the other side of the filament, that is our A band. And notice that it actually also involves a portion of our thin filament because we have this overlap between the thin filament and our thick filament. So the A band is the region that contains all the thick filaments in their entire length.