Smart ring Colmi R03 20.3 mm size 11 Gold — Colmi R03 smart ring, 20.3 mm, size 11, gold finish

Colmi R03 is a smart ring with a 20.3 mm inner diameter (size 11) and a gold finish. Made from a titanium alloy and weighing 4.7 g, the ring integrates heart rate, blood oxygen and sleep monitoring with activity tracking. It pairs with the QRing app (Android and iOS) via Bluetooth 5.0 and offers water resistance to 5ATM. The package includes the smart ring, a USB-C cable, a magnetic charging case and a user manual.

Advantages

The Colmi R03 combines a compact, lightweight titanium-alloy design with continuous health monitoring and multi-day battery life. It supports heart rate and SpO2 measurements, sleep phase analysis and 21 sports modes while providing water resistance for everyday wear and swimming. The included charging case extends the ring’s operating time by allowing multiple recharges on the go.

Suitable for

• Daily health monitoring (heart rate, blood oxygen, sleep)
• Activity tracking and workout logging
• Swimming and water-based activities (5ATM)
• Users preferring discreet on-finger wearable devices

Key specifications

• Inner diameter: 20.3 mm (size 11)
• Material: titanium alloy
• Weight: 4.7 g
• Bluetooth: 5.0
• Heart-rate sensor: Vcare VC30F
• Accelerometer: STK8321
• Memory: ROM 512 KB
• Ring battery: lithium‑polymer, 18 mAh, magnetic charging, ~5–7 days operating time
• Charging case battery: lithium‑polymer, 200 mAh, USB‑C, charges the ring multiple times
• Charging time (ring): about 1 hour
• Number of charging cycles (ring): over 300
• Water resistance: 5ATM
• Compatibility: Android 4.4 or later, iOS 8.0 or later, HarmonyOS
• App: QRing (generates daily, weekly and monthly reports)

How to use

Install the QRing app on a compatible Android or iOS device and pair the Colmi R03 via Bluetooth 5.0. Wear the ring on a finger with a comfortable fit; the inner diameter is 20.3 mm (size 11). Use the app to view continuous heart rate, blood oxygen and sleep data, select sports modes, and review activity reports. To recharge, place the ring in the magnetic charging case or connect the case to power via the included USB‑C cable.

Recommendations

For best measurement accuracy, wear the ring snugly but not too tight, keep the sensor area clean, and sync with the QRing app regularly. Avoid exposing the ring to strong chemicals or extreme temperatures despite its 5ATM water resistance.