Apple Watch

Features    GPS, GLONASS, Galileo, QZSS, and BeiDou   Compass   Always-on altimeter   Water resistant50 meters1   Blood oxygen sensor(Blood Oxygen app)2   Electrical heart sensor(ECG app)3   Third-generation optical heart sensor   International emergency calling5   Emergency SOS4   Accelerometerup to 32 g-forces with fall detection   Gyroscope   Ambient light sensor   Speaker   Microphone   Apple Pay   GymKit   Capacity 32GB    Display    41mm352 by 430 pixels904 sq mm...

Features    GPS, GLONASS, Galileo, and QZSS   Compass   Always-on altimeter   Water resistant50 meters1   Second-generation optical heart sensor   International emergency calling3   Emergency SOS2   Accelerometerup to 32 g-forces with fall detection   Gyroscope   Ambient light sensor   Speaker   Microphone   Apple Pay   GymKit   Capacity 32GB    Display    44mm   368 by 448 pixels   977 sq mm display area   40mm   324 by 394 pixels   759 sq mm display...

Features    GPS, GLONASS, Galileo, QZSS, and BeiDou   Compass   Always-on altimeter   Water resistant50 meters1   Blood oxygen sensor(Blood Oxygen app)2   Electrical heart sensor (ECG app)3   Third-generation optical heart sensor   International emergency calling5   Emergency SOS4   Accelerometerup to 32 g-forces with fall detection   Gyroscope   Ambient light sensor   Speaker   Microphone   Apple Pay   GymKit   Capacity 32GB    Display    45mm396 by 484 pixels1143 sq mm...

Features    40mm or 44mm case; over 30 percent larger displayfootnote2   Retina LTPO OLED display, 1000 nits   GPS   Ion-X glass display   S5 SiP with 64-bit dual-core processor; W3 wireless chip   Digital Crown with haptic feedback   Optical heart sensor   High and low heart rate notifications and irregular heart rhythm...