Garmin Forerunner 55

Battery life (Smartwatch mode): Up to 2 weeks
Daily suggested workouts: Yes (limited)
Display type: Sunlight readable, transflective memory-in-pixel (MIP)
Water resistance: Swimming, 5 ATM

Strap material: Silicone
Lenses: Chemically tempered glass
Quick release straps: Yes (20mm, industry standard)
Housing size, W x L x H 42 x 42 x 11.6 mm
Fits wrists with a circumference of 126-203 mm
Weight 37 g
Screen size, W x H 26.3mm (1.04″) diameter
Screen resolution, W x H 208 x 208 pixels
Color screen
GPS mode: Up to 20 hours
Charging method: Garmin charger with plug
Memory/history: 32 MB

Time/date
Time synchronization via GPS
Automatic summer time
Alarm clock
Timer
Stopwatch
Sunrise/sunset time

Heart rate monitor on the wrist (constant, every second)
Daily heart rate measurement at rest
Abnormal heart rate alerts: Yes (high and low)
Breathing rhythm (24X7)
Fitness age
Body battery™ energy monitor
Stress measurement throughout the day
Reminders for relaxation
Relaxation breathing timer
Sleep: Yes (advanced)
Hydration: Yes (in Garmin Connect™ and optional Connect IQ™ widget)
Women's health

For more information, visit the Garmin website:
https://www.garmin.com/nl-NL/p/741137#specs
Here are many more specifications about this very extensive luxury watch.