 The TXN model was only available in North America and is similar to the TX800, except it had a built in Sprint EVDO modem and antenna whereas the TX800 series lacked either.The previous TX600s and TX700s had built-in Cingular EDGE modems and antennas.The TXN models were also slightly heavier and thicker than all other TX models to accommodate the built-in Sprint EVDO WWAN modem.