Our carbon fiber spudger is overkill for this midframe, which actually cooperates nicely as we lever it out. It reveals:

What might be a rubber-ensconced alti-barometric sensor

A modular cable combo with two turntables switches and a microphone.

One of those switches comes with a bracket to enable the ECG function by closing the circuit of your finger and wrist

Hall effect sensors that track the rotation of the outer bezel

And the vibration motor, slightly glued to the frame.