These 4 models are multi-state area coverage that work with AT&T & T-Mobile towers. They can work with cell phones or any radio.
Peak PTT Nationwide 4G/3G Coverage – All Peak PTT devices also include 3G fallback.
Generally speaking the Peak PTT System can be enabled to work in other countries. Please let us know if you plan to use your devices outside of the United States, as they will require a special configuration.