Oura Ring (Gen 3, size 9)

This is the genuine Oura Ring (silver) with sensors that offer accurate heart rate, activity, sleep, and temperature data, in addition to blood oxygen (SP02), activity workout heart rate and inisights, readiness and restorative data and many more health insights. The following specs include:

Materials
Durable titanium
PVD Coating
Non-allergenic, non-metallic, seamless inner molding
Water resistant up to 100m/328 ft.
Weight & Dimensions
Width: 7.9mm
Thickness: 2.55mm — size of a wedding band
Weight: 4 to 6 grams (depending on ring size)
Connectivity
Bluetooth Low-Energy (Bluetooth Smart®)
Automatic firmware updates via Oura App
EMF-Safe and Allows Airplane Mode
Battery & Power
Up to 7 days of battery life*
Full charge in 20 to 80 minutes
Sensors
Green LEDs (optical heart rate sensor)
Red LED (blood oxygen sensor)
Infrared Photoplethysmography (PPG) sensors
Skin temperature sensors (negative temperature coefficient sensors)
Photodiodes
3D Accelerometer