"Apple Watch Series 9
45mm or 41mm case size
Aluminum metal or stainless steel
speaker
microphone
control:
Touch-responsive digital crown
side button
Click each other with two fingers twice
Execute Siri on device
monitor:
Always-on Retina LTPO OLED display
Welt design monitor
Ion-X glass surface (aluminum metal case)
Sapphire glass surface (stainless steel case)
Up to 2000 nits maximum brightness
Brightness as low as 1 nit
chip:
S9 SiP features a 64-bit dual-core processor
4 core Apple Neural Engine
64GB capacity
sensor:
Blood oxygen sensor and app Footnote 3
Electronic heart rate sensors and electrocardiogram apps Footnote 4
Third generation optical heart rate sensor
High or low heart rate notification Footnote 4
Arrhythmia Notice Footnote 5
sleep stages
Body temperature sensing Footnote 6
The compass app has waypoint and backtracking functions
Changqi altimeter
High g-force acceleration sensor
ambient light sensor
Splash, water and dust resistant:
Water resistant to 50 meters (suitable for swimming) Footnote 11
Dustproof IP6X Note 19
Connections and communications:
L1 GPS, GNSS, Galileo, and Beidou positioning system
LTE and UMTS Footnote 13
Wi-Fi 4 (802.11n)
Bluetooth 5.3
Second generation ultra-wideband chip Footnote 20
Apple Pay
GymKit
Power and battery life:
Built-in rechargeable lithium-ion battery
Typical use up to 18 hours Footnote 16
Low power mode provides up to 36 hours of use Note 16
USB-C magnetic fast charging cable"