Unreleased version of iOS 13.0 (17A512) Internal UI installed on a production iPhone X (D221AP) - Thanks to @URedditor for this build. #AppleInternal #AppleCollection 
Within the About page of settings, this extra hardware information appears, along with a QR code representing the device serial number.
The kernelcache from the filesystem dates to June 9th, 2019, exactly the same date as iOS 13.0 beta 2. Although, the XNU version is slightly newer.
Developer, Carrier, and Internal Settings:
A demo of the Internal Applications present on this build:
Among many of the of the internal applications present is Pearl ID Demo, seemingly used to test Face ID, or front facing camera sensors.
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