Apple has officially introduced its first foldable smartphone, the iPhone Duo, bringing a significant shift to user authentication. Departing from the TrueDepth camera module to maximize inner screen real estate, Apple replaced Face ID with a capacitive Touch ID sensor embedded in the side power button, paired with an instant auto-unlock feature powered by an authenticated Apple Watch.
The inner display of the iPhone Duo transitions from the bulky notch array to a low-profile FaceTime lens, eliminating traditional Face ID components. To ensure quick access across both folded 5.4-inch and unfolded 7.6-inch viewing angles, Apple introduced a proximity unlocking protocol: whenever a user is wearing an unlocked Apple Watch, the iPhone Duo unlocks immediately without requiring fingerprint verification.
This security interaction mirrors the existing auto-unlock mechanism on macOS, where wrist proximity grants trusted authentication. The side-mounted Touch ID remains active for primary financial authorizations and Apple Pay, creating a dual-layer credential loop between wearable telemetry and mobile hardware. Check hardware compatibility in our Apple Watch model identifier and optimize your device settings with our Apple Watch battery tips.
Preserved Benefit: Users gain instant access to both folded and unfolded screens without aiming biometric sensors at the face, accelerated by continuous Apple Watch authentication.
Explicit Trade-Off: Relying on wrist proximity authentication requires an active Apple Watch on the wrist; otherwise, users must physically tap the side Touch ID button for every wake event.
Beyond biometric security, the iPhone Duo measures just 5.2mm when opened—making it the thinnest iPhone ever engineered. A customized multi-gear carbon-fiber hinge built by Shin Zu Shing supports a crease-resistant inner OLED panel coated in an anti-reflective nano-texture finish.
Priced from $1,999, the device enters full commercial production backed by major component assembly across Hon Hai and optical modules from LARGAN Precision. Personalize your on-wrist setup with tactical layouts in our watch face packs or track your device charging cycles using our Apple Watch battery calculator.