When OnePlus launched the OnePlus 5T smartphone back in November 2017, they released it to the public with the Android 7.1.1 “Nougat” operating system, promising to open the public beta testing of an Android 8.0 “Oreo”-based OxygenOS in December. And they kept their promise, releasing the first OxygenOS Open Beta software update based on Android 8.0 “Oreo” for OnePlus 5T devices at the end of December 2017. The update includes December’s Android Security Patch too, just like the OxygenOS Open Beta 3 update for OnePlus 5, which brings OnePlus 5T’s face unlock feature.