OnePlus 8:
IN21AA IN2015 tools (international firmware):
android os 10: Oxygenos
android os 11: Oxygenos
IN21BA IN2013 tools (european firmware):
android os 10: Oxygenos
android os 11: Oxygenos
IN21DA IN2011 tools (indian firmware):
android os 10: Oxygenos
android os 11: Oxygenos
IN55CB IN2017 tools (USA T-Mbile TMO firmware):
android os 10: Oxygenos
IN67CD IN2019 tools (USA Verizon VZW firmware):
android os 10: Oxygenos
android os 11: Oxygenos
IN68CE tools (USA Visible firmware):
android os 10: Oxygenos
IN2010 tools (China firmware):
android os 11: ColorOS