Galaxy dual-SIM variant phones usually come from Asia or Europe, so you'll be buying a grey import which won't have a Samsung US warranty. I believe they're partially compatible with US bands and modes. It's been reported many times on AF that they won't work with Verizon or Sprint at all, because imported phones don't have the US CDMA bands and modes. GSM and HSDPA carriers like AT&T possibly, but you may need to check with your particular carrier or MVNO, if they'll register and activate an import phone for use on their network. Most other countries you just insert the SIM and that's it, but I think with US carriers they have to register and activate BYOD unlocked phones. Also I'm pretty sure that WiFi calling will not be supported at all with an unlocked imported phone.

 

Yes I think Its Compatible with all Bands.

 

I know for certain that dual-SIM Exynos variant S10 will NOT be compatible with Verizon or Sprint networks. And the only dual-SIM Snapdragon variant with CDMA/EVDO is China only.