DetailsDescriptionThe Oura Ring 4 Sizing Kit is a custom sizer that allows for you, and those around you, to find the ideal fit before purchasing. Oura Ring 4 sizes are slightly different from standard ring sizes, so it is important to size yourself using our sizing tool and to follow our instructions. A properly fitting Oura Ring 4 will result in the highest possible data accuracy, comfort, and overall experience. Easy steps to start your health journey today!1. Purchase the Oura Ring 4 Sizing Kit.2. Learn your Oura Ring 4 size by wearing a sizing ring for at least 24 hours.3. Purchase your Oura Ring 4 online or in a Target store near you.Looking for the best health tracker? Whether you’re searching for a sleep ring or fitness ring, Oura Ring is for you— this revolutionary smart ring that allows you to discreetly track your sleep, activity, recovery and stress, in style. SpecificationsShipping & ReturnsQ&A (9)