Trackimo GPS Tracker uses GSM cell phone network to send over the internet the information from the GPS tracker to the app. In the US, the T-Mobile network is used to provide cell coverage. Trackimo Mini Dog Tracker will work perfect as long�T-Mobile�network is available. This device should work anywhere your cell phone works but coverage cannot be 100% guaranteed. Your pet can be located anywhere in the world that it can connect to a 2G GSM cell network (except for: Canada, Japan, Korea, Singapore, Australia).