Although Card Phone is SIM-based, they don’t offer SIM cards to international customers, which means you’ll need to purchase something locally, if applicable. Even then, the cloud software platform will not be available and therefore unable to mask outgoing calls with your primary number.
Furthermore, since Card Phone was specifically designed as a second casual phone, it shouldn’t be considered a primary, standalone option. Further, you can currently only forward one phone to Card Phone and any voice mails won’t be accessible (except directly from your smartphone).
Important note: Based on their marketing approach and materials, it seems like Card Phone is geared toward an outdoor aesthetic. However, the device’s FAQ notes that “Sunlight will significantly reduce the visibility of the display and keypad,” so it might not be ideal in bright light.
Similarly, the FAQ also clarifies that “Emergency calls from your phone may not be possible in some areas or circumstances” and that “In less populated areas, the weaker digital signal deployed on higher frequencies may not be sufficient to reach a cell tower.”
As a result, they recommend, “Before traveling in remote or undeveloped areas, plan an alternate method of contacting emergency services personnel.”