Product Description

Overview

Experience the world's leading smart ring with the Oura Ring 4 in Silver (Size 6, 2024) — Smart Sensing 18-path multi-wavelength PPG, research-grade sleep staging, continuous heart rate and HRV, SpO2, body temperature, Readiness Score, 5–8 day battery, 10 ATM water resistance, and all-titanium construction. The Oura Ring 4 is the most refined and accurate smart ring available — delivering continuous, research-grade health monitoring from your finger using Smart Sensing technology that dynamically adapts its sensor algorithms to your unique physiology and skin tone for exceptional accuracy day and night. Fully titanium inside and out with recessed sensors for a smooth, comfortable interior, the Ring 4 is designed for genuine 24/7 wear at just 3.3 grams — through sleep, workouts, showers, and swimming. Important: full access to Oura's health insights requires an active Oura Membership subscription ($5.99/month or $69.99/year, after a first free month). The subscription is required for Readiness Score, Sleep Score, Activity Score, trend data, and actionable insights. The ring hardware alone will not deliver full functionality without a subscription. Please verify the subscription status of this account before purchasing and ensure you set up your own Oura account.

Key Features

• Smart Sensing — 18-Path Multi-Wavelength PPG — Research-Grade Accuracy: Oura Ring 4's Smart Sensing platform uses an 18-path multi-wavelength PPG subsystem that dynamically adapts its sensing algorithms to your unique finger structure, skin tone, and current activity — delivering continuously accurate heart rate, HRV, SpO2, and respiration data that independent peer-reviewed research has validated against gold-standard lab measurements.
• Sleep Staging + Readiness Score — Holistic Daily Health Intelligence: The Oura App translates overnight sensor data into detailed sleep staging (REM, deep, light sleep), a Readiness Score combining recovery, HRV, resting heart rate, and temperature trends, and actionable daily insights — delivering a comprehensive everyday picture of your recovery, stress load, and optimal performance windows.
• Continuous Heart Rate + HRV + SpO2 + Temperature — 24/7 Monitoring: Green and infrared PPG sensors alternate to measure heart rate continuously and HRV during sleep, red and infrared LEDs track blood oxygen (SpO2) overnight, and a digital temperature sensor monitors average body temperature variations — a comprehensive sensor suite for continuous everyday physiological tracking from a single lightweight ring.
• 5–8 Day Battery + 10 ATM Water Resistance: Up to 8 days of continuous health tracking per charge for uninterrupted everyday wear through multiple sleep cycles — and 10 ATM (100 metres) water resistance for confident wear in showers, pools, saunas, ice baths, and recreational diving, making the Oura Ring 4 genuinely all-day, all-environment wearable.
• All-Titanium Design — 3.3g Lightweight Everyday Comfort: Fully titanium inside and out with a PVD coating in Silver finish and recessed sensors for a smooth interior profile — the Oura Ring 4 weighs just 3.3 grams and is designed for genuine 24/7 comfort including during sleep, making it one of the least intrusive health wearables available.
• Size 6 + Oura App — iOS & Android: This ring is Size 6 — please verify your ring size using an Oura sizing kit before purchasing as smart rings are not adjustable. The Oura App on iOS and Android provides all health insights, trend analysis, sleep data, and account management. Note: Oura Membership subscription required for full feature access.

Specifications

Connectivity

• Bluetooth (to Oura App — iOS + Android)
• Magnetic USB-C Charging Clip
• 10 ATM Water Resistance (100 Metres)

What's Included

• (1) Oura Ring 4 — Silver (Size 6)
• (1) Magnetic USB-C Charging Cable

Does Not Include Default Packages

• Original Box
• OR4 Sizing Kit
• Oura Membership Subscription (purchased separately — required for full insights)

Condition Specifics

Good Refurbished — Good Condition: Professionally inspected, fully tested, and restored to 100% functionality. Titanium ring band shows moderate signs of cosmetic wear from normal use (such as surface scratches or minor scuffs). All sensors — heart rate, HRV, SpO2, temperature, and accelerometer — are fully functional and data-accurate. Charging functionality has been confirmed fully operational and performance is completely unaffected.

Warehouse Quality Statement: All units are fully tested and verified according to our internal quality standards. Heart rate, HRV, SpO2, body temperature, and accelerometer sensors have been confirmed fully operational and within expected accuracy parameters. Bluetooth connectivity and charging have been confirmed functional. We do not open devices during our inspection or refurbishment process. Important: this ring is Size 6 and is not adjustable — please verify your ring size before purchasing. Full access to Oura's health insights requires an active Oura Membership subscription ($5.99/month after first free month).