--- product_id: 814648943 title: "Ring 4 - Ceramic Midnight - Size 7 - Smart Ring | Non-Standard Fit – Measure with Oura Ring 4 Size Kit | Sleep, Heart Rate and Fitness Tracking Wearable | 8-Day Battery, iOS/Android Compatible" brand: "oura" price: "€ 858.50" currency: EUR in_stock: true reviews_count: 5 category: "Oura" url: https://www.desertcart.es/products/814648943-ring-4-ceramic-midnight-size-7-smart-ring-non-standard store_origin: ES region: Spain --- # Ring 4 - Ceramic Midnight - Size 7 - Smart Ring | Non-Standard Fit – Measure with Oura Ring 4 Size Kit | Sleep, Heart Rate and Fitness Tracking Wearable | 8-Day Battery, iOS/Android Compatible **Brand:** oura **Price:** € 858.50 **Availability:** ✅ In Stock ## Quick Answers - **What is this?** Ring 4 - Ceramic Midnight - Size 7 - Smart Ring | Non-Standard Fit – Measure with Oura Ring 4 Size Kit | Sleep, Heart Rate and Fitness Tracking Wearable | 8-Day Battery, iOS/Android Compatible by oura - **How much does it cost?** € 858.50 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.es](https://www.desertcart.es/products/814648943-ring-4-ceramic-midnight-size-7-smart-ring-non-standard) ## Best For - oura enthusiasts ## Why This Product - Trusted oura brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Description Oura Ring 4 - Ceramic Midnight - Size 7 - Smart Ring | Non-Standard Fit – Measure with Oura Ring 4 Size Kit | Sleep, Heart Rate and Fitness Tracking Wearable | 8-Day Battery, iOS/Android Compatible : desertcart.ae: Health Review: Wasn’t Sure at First—Now I’m So Glad I Have It Review: Beautiful ring, but ceramic finish doesn’t last ## Features - SIZE BEFORE YOU BUY - Oura Ring sizes are different from standard ring sizes. Size yourself with the Oura Ring 4 Sizing Kit - OURA MEMBERSHIP - First month of membership is included with purchase, for new members only. Or opt for the annual prepaid option. Membership is tied to your account via the Oura App, not your physical ring - ACCURACY - SMART SENSING - Oura tracks over 50 health metrics, including sleep, activity, stress, heart health, metabolic health,and women’s health metrics. Smart Sensing technology adapts to you — delivering accurate, continuous data, day and night - LONG LASTING BATTERY - With 5 to 8 days of battery life, no screens and no vibrations, Oura Ring 4 Ceramic allows you to focus on the present. From a workout to a night out — you’re free to forget it’s on. Until you start getting compliments - DESIGNED FOR 24/7 WEAR - Thoughtfully crafted in high-performance zirconia ceramic, Oura Ring 4 Ceramic combines refined elegance with everyday durability. The updated design is comfortable and is water resistant ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B0FKR336FD | | Additional Features | Activity Tracker, Heart Rate Tracker, Sleep Tracker, Stress Tracker, Women's Health Index | | Age Range Description | Adult | | Band Color | Midnight | | Band Material Type | Titanium | | Battery Average Life | 6.5 days | | Battery Cell Type | Lithium Polymer | | Battery Charge Time | 80 minutes | | Battery cell composition | Lithium Polymer | | Best Sellers Rank | #24,037 in Electronics ( See Top 100 in Electronics ) #64 in Wearable Tech Rings | | Brand | OURA | | Built-In Media | Information Booklet, Oura Ring 4 Ceramic, Oura Ring 4 Charger, Quick Start Guide, USB-C Cable | | Case Material Type | Titanium | | Color | Midnight | | Communication Feature | Bluetooth | | Compatible Devices | Oura Ring 4 Charging Case - Size 7, Smartphone | | Compatible Phone Models | Android Devices, iOS Devices | | Connectivity Technology | Bluetooth, USB | | Connectivity technology | Bluetooth, USB | | Country of Origin | Estonia | | Customer Reviews | 4.5 out of 5 stars 399 Reviews | | Display Type | No Display | | GPS | No GPS | | GPS Geotagging Functionality | No GPS | | Human Interface Input | Buttons | | Manufacturer | Oura | | Metrics Measured | Blood Oxygen (SpO2), Heart Rate, Sleep Duration, Stress | | Model Name | Oura Ring 4 Ceramic - Midnight - Size 7 | | Model Number | JZ90-57455-07 | | Operating System | Proprietary (Oura OS) | | Operating system | Proprietary (Oura OS) | | Shape | Round | | Special features | Activity Tracker, Heart Rate Tracker, Sleep Tracker, Stress Tracker, Women's Health Index | | Sport Type | Fitness | | Style Name | Minimalist | | Supported Application | Fitness Tracker | | Target Audience | Unisex Adults | | Unit Count | 1 Count | | Warranty Description | 2 year manufacturer warranty | | Warranty Type | Limited | | Water Resistance Depth | 100 Meters | | Water Resistance Level | Water Resistant | | Wearable Computer Type | Smart Ring | | Wireless Compability | Bluetooth | | Wireless communication standard | Bluetooth | ## Product Details - **Battery cell composition:** Lithium Polymer - **Connectivity technology:** Bluetooth, USB - **Operating system:** Proprietary (Oura OS) - **Special features:** Activity Tracker, Heart Rate Tracker, Sleep Tracker, Stress Tracker, Women's Health Index - **Wireless communication standard:** Bluetooth ## Images ![Ring 4 - Ceramic Midnight - Size 7 - Smart Ring | Non-Standard Fit – Measure with Oura Ring 4 Size Kit | Sleep, Heart Rate and Fitness Tracking Wearable | 8-Day Battery, iOS/Android Compatible - Image 1](https://m.media-amazon.com/images/I/61039+D-8-L.jpg) ## Available Options This product comes in different **Color, Size** options. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Wasn’t Sure at First—Now I’m So Glad I Have It *by D***N on 30 December 2025* ### ⭐⭐ Beautiful ring, but ceramic finish doesn’t last *by S***I on 5 April 2026* ### ⭐⭐⭐⭐ Przeznaczenie *by F***A on 4 April 2026* Bardzo polecam, pierścień gwarantuje bardzo dobre wsparcie w dbaniu o zdrowie. --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.es/products/814648943-ring-4-ceramic-midnight-size-7-smart-ring-non-standard](https://www.desertcart.es/products/814648943-ring-4-ceramic-midnight-size-7-smart-ring-non-standard) --- *Product available on Desertcart Spain* *Store origin: ES* *Last updated: 2026-05-26*