The Oura Ring 4 smart ring has been announced for $349 and will be released on October 15

Oura unveiled its new smart ring, the Oura Ring 4, on Thursday, which is available for a starting price of $349.

The company's rings track sleep, exercise, stress, heart health and other metrics to help users understand their bodies and make healthier choices. Oura Ring 4 has new sensors, a sleeker design, and up to eight days of battery life.

Oura said it has developed a new “Smart Sensing” platform that uses an updated algorithm and sensors to capture more accurate blood oxygen sensing readings, heart rate during the day and night, and breathing disturbances.

The sensors on the 3rd Gen Oura Ring are raised and look like little bumps, but the sensors on the Oura 4 Ring are flat. The company said this will give the ring a seamless interior design that is more comfortable to wear.

Oura Ring 4 is available in twelve sizes and six colors, including a new black. It's available for pre-order on Thursday and will start shipping on October 15.

In addition to the initial cost, users will have to pay for a membership of $5.99 per month or $69.99 per year. The first month is free. Customers can use flexible spending accounts and health savings accounts to pay for the ring and membership.

New look for the app

The company also announced a new design for its app, which is now rolling out to Oura members. Under the new design, users' data will be organized into three tabs called Today, Vitals, and My Health.

The Today tab will highlight relevant information based on the time of day, and includes shortcuts where people can quickly access information about their sleep, activity, readiness, stress, heart rate, and menstrual cycles if applicable. Users can dive into more detail about their data in the Vitals tab and access long-term metrics like sleep trends, cardiovascular age, sleep trends, and stress resilience in the My Health tab.

Oura said new features are coming to the app as well.

While exercising, members will not have to manually record their heart rate or the type of exercise they are completing. They will also be able to see their daily activity and movement within the daytime stress data. Ora said this will help improve users' understanding of how their behaviors and habits affect their stress.

Oura is also updating its reproductive health offerings to include a feature called the Fertile Window, which will help inform users of their chances of getting pregnant. The Fertility Window will provide users with an estimate of their fertile days, probability of pregnancy and detected ovulation day. Oura said the feature will be rolled out in the coming months, but members can sign up to join the waitlist for early access.

Oura Labs, where users can test new features, is now available on Android devices. This feature was previously only available on iPhones.