With a Stratus 1 or 1S, the GPS function will work anywhere, but the ADS-B receiver, which receives on 978 MHz, is not likely to detect any ADS-B data outside the USA because only the USA has adopted that frequency band.
With a Stratus 2 or 2S, the GPS function will work worldwide. The AHRS feature will work on both the 2 and 2S, but at this time, our Synthetic Vision is not available worldwide. The pressure altitude sensor will work worldwide on the 2S .
ADS-B outside of the USA uses the international standard of 1090ES (1090 MHz). The Stratus 2 or 2S ADS-B receivers will detect and display the position of aircraft in other countries that have 1090ES ADS-B Out equipment installed. Most of the air carrier aircraft have this equipment on-board.
Internationally, more aircraft are expected to equip to have 1090ES ADS-B Out for IFR operations in the coming years. This means that if you are using a Stratus 2 or 2S in countries with the ADS-B mandate, you will see a fair amount of the ADS-B traffic in their airspace. Unfortunately, none of the countries outside of the USA plan to have their ground stations broadcast TISB traffic for mode C equipped aircraft that are not ADS-B Out-equipped. They will also not be broadcasting any of the FISB weather products from their ground stations.
In summary, Stratus 2 or 2S receivers enables the display of 1090ES ADS-B Out-equipped aircraft outside of the USA, but do not display targets that are not so equipped (TISB).