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Oura - Ring 4 Ceramic - Smart Ring - Size Before You Buy with OR4 Sizing Kit - Size 10 - Midnight

Price
$389.99
Taxes and shipping calculated at checkout
Condition: Excellent

Oura - Ring 4 Ceramic - Smart Ring - Size Before You Buy with OR4 Sizing Kit - Size 10 - Midnight

Condition
Price
Excellent
$389.99
Good
$369.99
$389.99
Sold out
Eco-Save
$349.99
$389.99
Sold out
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Description

 

Oura Ring 4 Ceramic Smart Ring Size 10 - Midnight

OVERVIEW

The Oura Ring 4 Ceramic (Size 10, Midnight) is an elite biometric activity tracker engineered to seamlessly deliver continuous health telemetry and performance monitoring in a sleek, lightweight smart ring format. Crafted with a high-performance zirconia ceramic exterior and an allergen-free titanium inner shell, this device provides non-intrusive 24/7 monitoring for professionals and wellness-focused individuals. Driven by Oura's proprietary Smart Sensing technology and advanced optical sensor arrays, it delivers precise metrics on sleep architecture, heart rate variability, daily stress, and physical readiness. Offering an extended multi-day battery lifecycle and broad iOS/Android compatibility, this Grade A refurbished wearable delivers top-tier health management and exceptional fiscal value.

KEY FEATURES

  • High-Performance Zirconia Ceramic Build: Featuring a sleek Midnight ceramic exterior bonded to a biocompatible titanium interior, this smart ring ensures ultra-lightweight durability and non-intrusive 24/7 wearability.
  • Advanced Smart Sensing Platform: Equipped with multi-channel green, red, and infrared LEDs alongside a digital temperature sensor, the ring dynamically optimizes signal paths for accurate heart rate, SpO2, and sleep tracking.
  • Multi-Day Battery & Wireless Recharging: Experience up to 8 days of continuous telemetry on a single charge with rapid inductive magnetic dock recharging in 20 to 80 minutes.
  • Seamless Ecosystem & App Integration: Connect effortlessly via low-energy Bluetooth to sync complete health metrics, readiness scores, and automatic activity detection with iOS and Android wellness platforms.

SPECIFICATIONS

Device Type Smart Ring / Activity & Biometric Wearable
OS Version Proprietary Embedded Firmware (iOS & Android Compatible)
Processor / CPU Ultra-Low-Power Microcontroller with Smart Sensing Platform
RAM Size + Type System-Integrated Microcontroller SRAM
Storage Onboard Fixed Flash Memory (Local Data Caching)
Screen / Display Screenless Ergonomic Design
Touch Screen No
Color Midnight (Zirconia Ceramic Exterior / Titanium Interior)
Battery Integrated Rechargeable Lithium-Polymer (Up to 5–8 Days Battery Life)
Hardware Upgradeability Rating Non-Upgradable – Factory-sealed 100m (10 ATM) water-resistant casing
Memory Upgradeability Non-Upgradable – System-on-chip integrated architecture
Storage Upgradeability Non-Upgradable – Fixed onboard flash storage
Physical Ports & Expansion None (Utilizes magnetic inductive wireless dock interface)

CONNECTIVITY

  • Bluetooth Low Energy (BLE): Low-power wireless connection for localized data synchronization with iOS and Android devices via the Oura App.
  • Biometric Sensor Array: Integrated PPG green and infrared LEDs, red blood oxygen sensors, digital body temperature sensor, and 3D accelerometer.
  • EMF-Safe Wireless Management: Fully FCC-certified low-EMF operation with supported Airplane Mode configuration.

WHAT'S INCLUDED

  • Oura Ring 4 Ceramic (Size 10 - Midnight) Device
  • Size-Specific Magnetic Inductive Charging Dock
  • USB-C Charging Cable

DOES NOT INCLUDE

  • AC Wall Power Charging Adapter
  • Original Retail Box
  • Ring Sizing Kit

CONDITION

  • This item has been professionally tested by trained technicians and is fully functional. The device has been professionally restored to a very good condition with minimal signs of wear. This is a refurbished product. It has been inspected, tested, and restored to full working condition. Minor cosmetic imperfections may be present. Devices will have some variation in appearance.
See Specifications
Brand Oura
Title Oura - Ring 4 Ceramic - Smart Ring - Size Before You Buy with OR4 Sizing Kit - Size 10 - Midnight
Model JZ90-57455-10
Color Midnight

FAQ

What kind of warranty/guarantee do you offer?

At R3NEW, most transactions are backed by a 1-year warranty, covering technical defects and malfunctions, while every purchase includes a 30-day guarantee. Our warranty is designed to give you peace of mind, ensuring the reliability and longevity of your device.

What's the difference between the conditions? (Excellent, Good, EcoSave)

Great question! Let us break down the difference.

Excellent: Our Excellent condition devices offer a pristine user experience that rivals new units, boasting a flawless appearance with no visible scratches on the display or body. Each device undergoes rigorous testing to ensure it operates like new, giving you peace of mind with a full year of warranty coverage. It’s an ideal choice for those seeking near-new quality without the brand-new price tag

Good: Devices in Good condition are a great compromise between cost and quality. You might find a few minor scratches or slight nicks on the body or display, but these are purely cosmetic and don’t affect the device’s operation. We suggest using a case to bring its external appearance closer to 'like new.' Rest assured, every device meets our strict functional standards and comes with a one-year warranty for functionality

EcoSave: Opt for our EcoSave condition if you want to maximize value while minimizing environmental impact. These devices show visible signs of use, such as scratches or dents, which are purely cosmetic and can often be concealed with a case. Each device has passed our comprehensive functional tests and is backed by a one-year warranty, ensuring it works perfectly for you while also being kind to the planet.

Can I trust R3NEW?

We've sold electronics for over 15 years and are one of top trusted sources of certified refurbished electronics. Plus, with a 30-day guarantee and 12 month warranty, you can shop with peace of mind. If you have any issues at all, just email our support team and we'll help you out.