Inquiry Key Facts SCG-601 with 1SIM 1Tel; reverse polarity (12KHz is option, Quad band GSM 900/1800MHz or 850/1900MHz to connect analog PBX, Tel, Payphone, VoIP or Billing system Packing Detail Main Functions: Suitable for GSM 900/1800MHz or 850/1900MHz PSTN network, using SIM card Making & answering calls after connecting to telephone set Can make phone calls via GSM or PSTN network by choice or according to the routing parameter)