Oura Ring 4 [Size 5] (Black)

Oura Ring 4 Smart Fitness Tracker Ring - Revolutionary Smart Sensing Health Monitoring Wearable with 30+ Biometrics. Advanced research-grade sensors track heart rate, HRV, SpO2, body temperature, sleep quality, stress, metabolic health, women's health 24/7. Smart Sensing technology adapts to your unique physiology for 120% improved signal accuracy. Lightweight medical-grade titanium smart ring (3.3-5.2g) with 5-8 days battery life, 20-80min fast charging. Waterproof to 100m, Bluetooth connectivity, hypoallergenic titanium design. Compatible with iPhone/Android Oura App for personalized health insights and continuous monitoring. Available in 6 titanium colors, sizes 4-15. Ultra-thin 7.9mm width, 2.88mm thickness. No screens, no vibrations - invisible health tracking alternative to smartwatch. Perfect for accurate sleep analysis, continuous fitness monitoring, and personalized wellness optimization.