AsunTracker Long Standby Time Dog Cat Pet Personal GPS Tracker/IOS/Andriod App Free Website Service Location Based service also named A-GPS, when tracker in underground or tunnel ,can get location by AGPS. Real time tracking it by cell phone and platform . Also can support get location every 5 seconds, and the Rastreador Localizador GPS accuracy is about 5m Can check and replay within one year history of route of device ,by web monitor center Can hear the voice around the tracker by cell phone . Also support communication with the tracker by cell phone (OEM),Check the location with google map on mobile. Set up a geo-fence for the unit to restrict its movements within a district ,unit will send a message to the authorized numberwhen it breaches the district.