Specilized SIM card in case of misuse in mobile phones after decrypt. Attached small keyboard to input more conveniently. Phone book storing up to 100 pieces of numbers. Normally ringing and receiving calls even when the handset is off hook. Support to connect external ring loudspeaker (optional) in the loud surroundings (Such as in vessels or vehicles) Moisture-proof(optional). Support carrier lock. Receiving and sending short messages. Friendly interface using both text and images. Incoming caller ID, dialed calls, missed calls records Prefix IP ahead of the long distance call. GSM900/DCS1800MHz dual mode adaptation. Hands free and redial function. 128*64 LCD with background light showing five lines of calling information, date and time. Displaying battery level and signal strength. Network management to modify parameters remotely. Call barring and forwarding. internal or external antenna Low power design. Connecting to outer power supply or using backup batteries. Intelligent power management. Detecting the batteries to recharge or discharge automatically. Using industrial wireless module. 850/1900mHZ frequency optional.