TopFlyTech T8503 tried to build it really well and simple. This tracker has a SOS button and mutual voice communication feature. Another special thing is RFID tag availability.
Its 2100 mAh battery is rechargeable with USB port. The device is protected from dust and water that may be useful in bad-weather conditions.
To set the tracker send the following commands by SMS messages, the sample setup the device password is TK5n, this password is the default
Set the time zone UTC-0
Set the operator APN
Set the GPRS server
Set the update interval, 60 seconds