Circular's New Smart Ring Can Pay for Your Coffee and Track Your Heart
Circular has announced its Ring 3 Series, the follow-up to the Ring 2 that appeared at CES 2025. The lineup comes in two versions: the Pro, which keeps the health-tracking features of the earlier ring, and a slimmer, lighter model called the Slim. Both are expected to go on sale in early 2027, with pricing not yet announced The Verge.
Both the Pro and Slim can make contactless payments, meaning you can tap the ring against a payment terminal just like you would with a phone or contactless card. No phone or wallet needed. The rings also vibrate to alert you for things like alarms, medication reminders, and guided breathing exercises The Verge. The thinking is that a ring is something people will keep on through sleep, showers, and exercise, which gives the light-based sensors inside the ring the best chance to read the body accurately Circular.
The Ring 3 Pro is made from titanium, a strong but lightweight metal, and comes in gold, rose gold, silver, and black finishes. Battery life on the Pro has been extended from seven days on the previous model to up to 12 days, even though it uses a smaller battery. A wireless charging case can recharge the ring five to six times before the case itself needs to be plugged in The Verge.
The Pro keeps the Ring 2's health-tracking features, including upgraded sensors and FDA-cleared detection of atrial fibrillation, an irregular heart rhythm that can raise the risk of stroke. The FDA clearance is documented in 510(k) Premarket Notification K221361, filed by applicant Bodimetrics under regulation number 870.2700 FDA. The ring takes a reading of your heart's electrical activity (an ECG) by having you place one finger from each hand on the ring for about forty seconds, then it flags signs of atrial fibrillation Circular. Circular markets its Ring 2 as the world's first smart ring with this kind of heart-rhythm detection Circular.
The Ring 3 Slim takes a different approach. It is slimmer, thinner, and lighter than the Pro and delivers up to 10 days of battery life. Instead of titanium, the Slim uses a nonmetallic material Circular calls a "biocompatible epoxy" on the inside of the ring. It uses light-based sensors to measure heart rate and blood oxygen levels but does not include the ECG sensor or atrial fibrillation detection found on the Pro The Verge.
Both Ring 3 models track skin temperature, daily activity, sleep, and heart rate variability, which is the variation in timing between heartbeats and can hint at how stressed or recovered your body is. The light-based sensors measure heart rate, heart rate variability, and blood oxygen continuously through the night. Skin temperature is compared to your own personal baseline, which the company says can be an early sign of illness or a phase of the menstrual cycle. A motion sensor tracks sleep stages, workouts, and steps automatically. The vibrating alarm is felt on your finger but not heard by anyone else in the room The Verge Circular.
CNET published its coverage of the Circular Ring 3 Pro and Slim on September 2, 2026, reporting that the models add contactless payments and vibrating feedback CNET. The Verge followed with its reporting on September 3, 2026.
The broader context here is a smart ring market trying to balance two things: packing in enough sensors to track your health, and keeping the ring small enough that people actually want to wear it. Adding payments moves the ring beyond just collecting data and into something you use actively in daily life, a shift we watched happen with smartwatches about ten years ago. The split into Pro and Slim models suggests that manufacturers are recognizing the sensors and battery you include directly determine how big the ring has to be.
Worth flagging is the Pro's battery jump from seven to 12 days alongside a smaller battery. If that figure holds up in independent testing, the power efficiency is notable for a device that includes a heart-rhythm sensor, continuous light-based health tracking, and a payment chip inside a titanium ring. The Slim's removal of the heart-rhythm sensor to get thinner suggests that medical-grade health features are the main thing limiting how small these wearables can get.
In my view, splitting the lineup into two models is a practical response to what has held smart rings back. The Slim, with its lighter build and simpler sensors, lowers the barrier for people who mainly want sleep and activity tracking. The Pro keeps the regulatory clearances and tough materials for users who care about heart health. What this ultimately enables is a wider path into finger-based health tracking, a category that has struggled to balance medical usefulness with a design small enough to wear all day and night.
