A few days ago, OnePlus co-founder Carl Pei announced that the OnePlus 5T's face unlock feature would arrive on the 5, "due to popular demand." The feature was not included in the phone's Oreo update, but it has now arrived in an OxygenOS Open Beta for the OnePlus 5.
Open Beta 3 was released earlier today, and clocks in at 1.58GB. The most notable feature is face unlock, but there are some other nice improvements as well. The December security patch level is included, issues with 5GHz Wi-Fi connections and vibrations have been resolved, and the Recorder app now has an app shortcut.
You can download Open Beta 3 for the OnePlus 5 at the source link below. Keep in mind that this is beta software, so if you want a stable phone, you should probably hold off.