GSM 900/1800Mhz(GSM 850/1900Mhz optional) 1.Random PIN code protection. 2.The phone has phone incoming or dialing call bar functions. 3.Volume adjustment. 4.Handsfree dialing and redial functions. 5.LCD displaying date and time. 6.Support carrier locking. 7.Automatically add IP access number ahead of long distance calls. 8.Intelligent power management. Detecting the batteries to recharge or discharge automatically. 9.Displaying battery level and signal strength. 10.Calls records. 11.incoming caller ID. 12.Setting date, time and clock. 13.Quickly responds after pressing the keys. 14.Internal or external antenna. 15.Promoting voice quality by echo suppressing and digital encryption technologies. 16.Appearance in good taste. 17.Convenient operations. 18.Using industrial wireless module.