Complex sentence: The American version, CU720, offered by AT&T does not have this, and must use the primary camera for its video calling service and has expandable memory (microSD) up to 4GB.
Split into simpler sentences: The American version, CU720, offered by AT&T does not have this, and must use the primary camera for its video calling service. It has expandable memory (microSD) up to 4GB.