Support specialized SIM card (have applied for patent) Off hook ringing. Support to connect external ring loudspeaker in the loud surroundings Such as in vessels or vehicles). LCD displaying coming calls and the number of calls. Store up to 600 pieces of billing record. Setting and displaying time and date; calling back, redail and hands- free functions. Support carrier lock. Support barred call. Support remote network management. Support IP prefix. GSM900/DCS1800MHz dual mode adaptation. Support handsfree calling and hanging up. intelligent power management. Support network management through serial port and remote management. 850/1900mHZ frequency optional. Setting or modifying parameters and rates in two modes: SMS and Serial port. Setting free calls. Setting Barred calls. Setting password for rate inquiring. Setting discount for different period of time. Store up to 600 pieces of billing record. Using industrial mobile module.