Long Battery Life Up to 7 days of battery means you can track your health 24/7 without charging every night. Built to Last Oura Ring is made of titanium: super strong, non-allergenic, lighter than the average wedding band. Pinpoint Accuracy Oura's research-grade sensors track it all: temperature-trends, heart rate, daily activity and recovery, sleep quality, menstrual cycles, even stress. Always Wearable Water resistant and tough enough to withstand altitude, heat, and cold, Oura tracks your biometrics wherever adventure takes you. Traded mine for a new color and bigger size. Works perfectly, just a bit of cosmetic wear. Comes with charger and box.