We are more used to GPS tracker these days, but one especially useful function that some have is 2 way or SOS calling. A GPS tracking device with this function will not only display its positions via GPS signal, but can also act as a variety of emergency...

Many average consumers are already getting familiar with GPS because this technology helps people to get their daily outdoor tasks done faster and safer. As long as the GPS device stays accurate, users should have no trouble tracking their current position....