Oura Ring 4 Silver, size 12

The Oura Ring 4 is a compact smart ring for continuous monitoring of sleep, heart activity, temperature trends and daily movement. It’s aimed at users who want detailed biometric insights around the clock without wearing a wrist device — lightweight and designed for 24/7 wear.

Made with titanium and recessed sensors, the Ring 4 provides SpO2, continuous heart rate and HRV monitoring, a digital temperature sensor and a motion sensor. Data syncs to the Oura app for sleep, readiness, nighttime breathing analysis and cycle insights. Battery life typically ranges from 5–8 days, with charging usually taking 20–80 minutes.

The ring is water resistant to 100 m and comes in multiple finishes; this listing is for the Silver finish in size 12. Connectivity and firmware updates use Bluetooth Low Energy via the Oura mobile app (iOS/Android).

Specifications

• Material: Non‑allergenic titanium (inner and outer surfaces)
• Sensors: Red & IR LEDs (SpO2), Green & Red LEDs (HR, HRV, respiration), digital temperature sensor, accelerometer
• Thickness: 2.88 mm
• Width: 7.90 mm
• Weight: 3.3–5.2 g (varies by size)
• Battery life: 5–8 days
• Charge time: Typically 20–80 minutes
• Water resistance: Up to 100 m / 328 ft
• Connectivity: Bluetooth Low Energy
• Compatibility: Oura App on iOS and Android; integrates with third‑party apps
• Finish: Silver
• Size: Size 12