chipset MSM6280 protocol WCDMA UMTS chipset: MSM 6280 frequency 2100MHz+ edge850/ 900/ 1800/ 1900MHz ransmit rate Max DL7.2Mbps nterface USB2.0 others SMS Flow shows, VOICE , 8G TF/ SD-CARD Applicable voltage 5V size 89* 47* 11.5mm temperature -20--55° c weight 30g Compatible system WINDOWS2000/ XP/ VISTA/ Win7 32/ 64 color black/ white