Seidio CONVERT Extended Case for HTC Thunderbolt (fits 2750 / 3200 mAh batteries) for $23.99

True versatility emerges in the cutting-edge design of the Seidio CONVERT Extended. An industry-first, the CONVERT Extended features two smartphone cases in one - a sleek case for everyday protection and a heavy-duty case for the demands of the outdoors or rugged professions. While using your OEM 2750mAh or Seidio Innocell Extended Life Battery, start with our SURFACE   Extended case and upgrade by adding a layer of shock-absorbing silicone and a precision-fit skeleton.