Apple Watch Series 8 has an innovative new sensor that tracks your temperature while you sleep, so you can see changes over time. Cycle Tracking uses this data to provide a retrospective estimate of when you likely ovulated, which can be helpful for family planning.

Dimensions: 1.61 x 1.38 x 0.42 inches

Weight: 1.13 oz (32.0 g)

Resistance: Water, Dust; IP6X

FEATURES: Sensors Accelerometer, gyro, heart rate, barometer, always-on altimeter, compass, SpO2, VO2max, temperature (body) Temperature sensing (0.01° accuracy) Natural language commands and dictation (talking mode)Ultra Wideband (UWB) support

BATTERY Type: Li-Ion 308 mAh, non-removable, Charging Wireless fast charging