Features: 1. Tri-band supported: GSM900/DCS1800/PCS1900 MHZ. 2. Supports GSM data and voice transmitting, SMS supported, with wireless fax function etc. 3. More optional services: Call Barring, Multi-Party calls, call waiting, and call Hold, Explicit Call Transfer etc. 4. Provides complete application software. 5. High quality chipset to run excellent performance and capability 6. Small and exquisite shape enables to insert the PC slot entirely and Inner retractable Antenna supporting 360?rotation for an intact integration with notebook. 7. All-new aluminum heat sink structure for long time internet access requirements. 8. Standard USB interface, supporting the hot-plug gable insert or draw out at anytime without OS rebooting. OS requirement: Windows 2000/XP Dimension: 54.0 x 54.0 x 11.0 mm.