GPS Real-Time Tracker GSM/GPRS - Track Unit Anywhere with PC/Smartphone or SMS G810 Tracing Position, Monitoring, Playback Tracks and other operations via Internet. Receiving feedback while device is in movement. Set a limited area, alarms while crossing over the area TDTV1 is a complete cell phone, configured with Speaker, MIC, buttons for - Calling and Hang-up. Alarm Notifications: While enters dead zone and low battery.