Pre-owned headphones in good condition.
Audio Technology:
Active Noise Cancellation
Transparency mode
Adaptive EQ
Vent system for pressure equalization
Custom high-excursion Apple driver
Custom high dynamic range amplifier
Spatial audio with dynamic head tracking
Sensors:
Dual beamforming microphones
Inward-facing microphone
Dual optical sensors
Motion-detecting accelerometer
Speech-detecting accelerometer
Force sensor
Chip:
H1 headphone chip