This data then gets fed to the Oura App on your Android phone or iPhone to give you actionable insights that can help improve sleep and performance. The Oura Ring is made of titanium and is non allergenic, non-metallic and has a seamless inner molding. The ring has sensors for infrared optical pulse measurement, a 3D accelerometer, gyroscope and body temperature. The Oura Ring will last for up to 1 week on a full charge, typically charges in 30 – 60 minutes and can also charge wirelessly. It connects to your smart phone using Bluetooth Low-Energy smart technology and has a ring airplane mode for when you’re travelling. All data is collected autonomously using the built-in memory and can store data for up to 6 weeks. The ring is ultra light weight, weighing 4 to 6 grams (depending on the exact style) is 7.9mm wide and 2.5mm thick. The ring is available in 8 sizes, ranging from US6 to US13.