Circular's New Smart Rings: One for Your Health, One for Everyday Wear

On September 3, 2026, at a technology trade show in Berlin, a company called Circular introduced two new smart rings: the Ring 3 Pro and the Ring 3 Slim. Both rings let you pay for things by tapping your finger against a card reader, just like a contactless payment card or a phone. Both also vibrate on your finger to alert you about alarms, medication reminders, health warnings, and guided breathing exercises. Circular has not yet said how much the rings will cost or when you can pre-order them, but they should be available in early 2027.

The Ring 3 Pro is the more health-focused of the two. It can check your heart's rhythm for a condition called atrial fibrillation, or AFib, which is an irregular heartbeat that can increase the risk of stroke. You do this by wearing the ring on one finger and touching it with another finger from your opposite hand for about forty seconds. The ring then tells you whether it detected signs of AFib. This feature has been cleared by the FDA in the United States and certified as a medical device in Europe, which means it meets government standards for medical accuracy.

The Pro also tracks blood pressure trends, glucose (blood sugar) levels, and detailed sleep patterns. Throughout the night it continuously measures your heart rate, the variation in time between your heartbeats, and your blood oxygen level using small light sensors that read blood flow through your skin. It also measures your skin temperature and compares it to your own personal normal level, which Circular says can be an early warning sign of illness or a particular phase of the menstrual cycle. The ring uses motion sensors to track sleep stages, workouts, and steps automatically, so you do not have to manually log activities.

The Pro lasts up to 12 days on a single charge, up from seven days on the previous model, the Ring 2. The Ring 2 was described by Circular as the world's first smart ring with heart rhythm detection.

The Ring 3 Slim is thinner and lighter than the Pro. CEO Amaury Kosman said it was made for people who want a fashionable smart ring with basic wellness information and the ability to pay by tapping, rather than every health feature. The Slim tracks sleep, heart rate, blood oxygen, skin temperature, and daily activity, with up to 10 days of battery life. Neither the Pro nor the Slim requires a monthly subscription to use their core health features.

Both rings are made of titanium steel, can survive being underwater up to 50 metres deep, charge wirelessly, and come in sizes 6 through 14. They are available in gold, rose gold, silver, and black. The vibration motor in both rings can wake you with a silent alarm felt only on your finger, not noticed by anyone else in the room. Circular says the finger is a good place for a device because the skin there gives the best readings for light-based sensors, and because people are more likely to keep a ring on through sleep, showers, exercise, and daily life.

The smart ring market has become crowded. Oura, the best-known smart ring brand, launched its Ring 5, and another company called RingConn introduced its Gen 3 model, both before Circular's announcement. The pressure from competitors is visible in Circular's decision to make two versions: one loaded with medical-grade sensors and one that keeps things simple but still includes tap-to-pay. The decision not to charge a subscription for core health features is aimed directly at Oura, which charges a monthly fee.

The Ring 3 Pro's health sensors are the more ambitious of the two. Blood pressure tracking and glucose tracking in a ring are still new territory for the entire wearable industry, and Circular has not explained how those features actually work. The heart rhythm check, however, has real government medical approval behind it, which sets the Pro apart from competitors whose health claims have not been held to that standard. The 12-day battery claim, if it holds up in everyday use, would give the Pro a clear advantage over most other smart rings, which typically last about a week between charges.

The Slim, by contrast, looks like a play for a wider audience. Kosman's description of it as a "fashionable smart ring with essential wellness insights" targets people who find the Pro's health sensors either unnecessary or too bulky. The Slim's lighter build and shorter battery life trade medical-level detail for something easier to wear every day, while still offering the tap-to-pay feature that has become a basic expectation in smart rings.

Circular already makes a separate ring devoted only to contactless payments. By adding payments into the health-focused Ring 3 series, the company is combining two devices into one, which makes sense for a company trying to offer a bit of everything rather than specializing.

Pricing will be the deciding factor. Circular has not shared any numbers, and the smart ring market ranges from expensive rings that also charge monthly fees to simpler one-time purchases. With the rings not arriving until early 2027, the company has given competitors months to respond, and has given itself time to settle on prices that can support both the health-focused Pro and the simpler Slim.