The smart stainless-steel Ring One tracks heart rate, heart rate variability, blood oxygen, body temperature, and sleep around the clock. Data is analyzed free of charge in the Hama Active app, with no subscription required. It supports 120 sports, counts steps, and is water-resistant up to 5 ATM. Vibration alerts provide discreet notifications, while the battery lasts up to four days. Available in U.S. ring sizes 7–12. Retails for around $302 USD
“Ring One” Smart Ring
