Just a few minutes ago we brought you more information on the HTC HD2 extended battery. At the time we did not have images, but we have now been able to source the official images of the HTC HD2 BP E400 Extended Battery.
Looks like they have done good job – take a look below. (To enlarge, just click the image)
With a 2300mAh capacity, a replacement back cover and kickstand, if you want one for your HTC HD2 you can order yours here

