I happen to come across this unit and i personally have one. It works! It gives us the GPS coordinates when we are outdoors. All we need to do is send a SMS to the tracker and a SMS with the GPS coordinates will come back to our phone. This tracker also allows the child to call 3 numbers (ie to mum, dad or home) or all 3 if SOS is activated. Hope this helps. The GPS KiDz Tracker ( http://tinyurl.com/5rzcj4z ) is useful when the child goes on an excursion for us to have a peace of mind!