Karbonn K9 Smart 4G was officially announced in December 2016, Device released in December 2016Mobile Network Support and BandKarbonn K9 Smart 4G have Dual Micro SIM Card Slots,Karbonn K9 Smart 4G support all GSM Based network providers. Karbonn K9 Smart 4G mobile device support 2G Band Frequency at GSM 900,GSM 1800 and Hight Speed 3G Network Band at HSDPA 900,HSDPA 2100,Karbonn K9 Smart 4G also support LTE based 4G Networks Support at Frequency level LTE 1800,LTE 2300,