Allview Viper V1 S 4G was officially announced in September 2014, Device released in September 2014Mobile Network Support and BandAllview Viper V1 S 4G have Dual Micro SIM Card Slots,Allview Viper V1 S 4G support all GSM Based network providers. Allview Viper V1 S 4G mobile device support 2G Band Frequency at GSM 850,GSM 900,GSM 1800,GSM 1900 and Hight Speed 3G Network Band at HSDPA 900,HSDPA 2100,Allview Viper V1 S 4G also support LTE based 4G Networks Support at Frequency