Circular is debuting its Series 3 smart ring at IFA, featuring NFC mobile payments compatible with Visa and Master Card products. The ring combines health tracking with payment functionality, allowing users to make purchases without choosing between features. It includes a vibration motor for silent alarms and reminders, nearly doubling battery life to 12 days. The titanium ring is water resistant to 50 meters and available in sizes six through 14.

The fully-featured Ring 3 Pro measures 6.8mm wide and 2.78mm thick, while the slimmer Ring 3 Slim is 5.9mm wide and 2.35mm thick, weighing about half as much. However, the Slim version loses the ECG capability and haptic motor. Both models ship with a charging case containing a 700mAh battery. Both rings include sleep and activity tracking, blood pressure and glucose trend monitoring, plus Circular's unique single-line ECG feature.

Neither model's price or availability has been announced, though they're expected to launch in the coming months, possibly ahead of the holiday shopping season.