new in box with extenders and chargers. Retail: $300 “The circul+ Smart Ring is the only ring oximeter with continuous blood oxygenation (SpO2) and Heart Rate (HR) tracking for sleep, activity, and overall wellness. Circul+ helps improve your personal health and wellbeing by providing exercise and sleep quality metrics that can enhance mental clarity and energy levels. Effective daily care metrics for heart and lung health including heart rate monitoring, steps and continuous SpO2 monitoring.”