More Accurate From the Finger The finger is the ideal source of accurate heart rate data, more sensitive to movement, and more accurate across all skin tones. Long Battery Life Up to 7 days battery life. Fast charging gives you a full charge in just 20-80 minutes.* Research-Grade Sensors Monitoring your sleep, activity, recovery, temperature, heart rate, stress, and more — with precise accuracy. Award-Winning Design 24/7 comfort, ultra-lightweight, water resistant, and durable. Oura"s timeless ring design works for any occasion, for work out to night out. Tech Specs 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