... NO.FunctionFrequency(MHz)Q2303-32SMS(600pcs/hour by one port)900/1800Q2403-32SMS, MMS900/1800Q2406-32SMS , MMS, TCP Protocol900/1800Q24plus- ... 32SMS, MMS, TCP Protocol, remote control850/900/1800/1900 Key Features♦Just like 32 single-channel equipments ... be demolished♦Industrial chassis, elegant shell♦GSM frequency: 850/900/1800/1900 MHz♦32 x SIM card(big/small) slots ...