In order to hide a GPS tracker inside a shoe insole in a way that is comfortable for the wearer we developed the thinnest GPS tracker in the world! We needed the smallest device and that uses a small “cell phone style” battery. For this reason, we employ a 2G cellular device which is small enough to fit and does not require a large battery to function. (3G draws much more power and at present may not last more than 1 day per charge). Yes, 2G cellular coverage is no longer available to the USA consumer. Fortunately, GTX Corp partners with T-Mobile’s business division which still hosts a large 2G network nationwide- keep in mind, the original 2G network is still larger than the current 3G / 4G networks. The only challenge is that T-Mobile does not maintain a map of their 2G coverage area, therefore, the only way to know if GPS SmartSole will work for you is to buy it and test it in your area. Yes, we are currently developing a 3G device and strive to make it small enough and power efficient enough to work for future models of GPS SmartSole. It is our core vision and motivation to develop a practical and universal tool to help caregivers, but we are limited to the device and battery technology available at this time.