Does it have Oxygen or Hydrogen OS? Is there any differences between models on sale in Europe?
Oxygen OS. no difference.
See below this model supports
4G BANDS
LTE band 1(2100), 2(1900), 3(1800), 4(1700/2100), 5(850), 7(2600), 8(900), 12(700), 17(700), 18(800), 19(800), 20(800), 26(850), 34(2000), 38(2600), 39(1900), 40(2300), 41(2500)
5G BANDS
5G band 41(2500), 78(3500), 79(4700); SA/NSA
Registered Customers