myFirst Fone R1 (Europe/Asia/Africa) supports the following - 2G: 900/1800MHz | 3G: 2100/1900 WCDMA | 4G LTE Bands: B1, B3, B7, B8, B20. Do check with the preferred local mobile network operator if the SIM card is on the supported bandwidth.
For myFirst Fone R1 (Japan), it supports 4G LTE Bands: B1, B3, B8, B18, B19.
For myFirst Fone R1 (US/Mexico/Canada), it supports 4G LTE Bands: B2, B4, B5, B12, B17. ** The launching date for the US/Mexico/Canada model is yet to be confirmed **
R1 needs a Nano SIM card that comes with Talk Time and Data. Caller ID is also needed for some countries.
R1 would not be able to function properly on a Data-only SIM card or Shared SIM card (SIM card with the same number across multiple devices).
* For Singapore user, TPG SIM card is tentatively not compatible with R1