---
product_id: 664628456
title: "Oura Ring 4 - Black - Size 4 - Smart Ring, Sleep, Activity, Women’s Health, AI Advisor, Up to 8 Days of Battery Life, Size Before You Buy, Android & iOS Compatible"
brand: "oura"
price: "R$5753"
currency: BRL
in_stock: true
reviews_count: 10
category: "Oura"
url: https://www.desertcart.com.br/products/664628456-oura-ring-4-black-size-4-smart-ring-sleep-activity
store_origin: BR
region: Brazil
---

# 8-day battery life custom titanium sizing 50+ health metrics tracked Oura Ring 4 - Black - Size 4 - Smart Ring, Sleep, Activity, Women’s Health, AI Advisor, Up to 8 Days of Battery Life, Size Before You Buy, Android & iOS Compatible

**Brand:** oura
**Price:** R$5753
**Availability:** ✅ In Stock

## Summary

> 💡 Oura Ring 4: The smart ring that knows you better than you do.

## Quick Answers

- **What is this?** Oura Ring 4 - Black - Size 4 - Smart Ring, Sleep, Activity, Women’s Health, AI Advisor, Up to 8 Days of Battery Life, Size Before You Buy, Android & iOS Compatible by oura
- **How much does it cost?** R$5753 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.com.br](https://www.desertcart.com.br/products/664628456-oura-ring-4-black-size-4-smart-ring-sleep-activity)

## Best For

- oura enthusiasts

## Why This Product

- Trusted oura brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Unplug & Go:** Up to 8 days of battery life means you stay focused on life, not charging—wear it through workouts, meetings, and nights out.
- • **Deep Health Insights:** Track over 50 health metrics including sleep, stress, heart, and women’s health with adaptive Smart Sensing technology.
- • **Seamless Style Switch:** Multi-ring support lets you effortlessly swap finishes via the app—match your ring to your mood or outfit in seconds.
- • **Membership Perks Included:** First month free membership unlocks personalized insights and guided meditations—stay ahead in your wellness journey.
- • **Precision Fit, Every Time:** Unique sizing kit ensures your Oura Ring 4 fits like a second skin—no guesswork, just perfect comfort.

## Overview

The Oura Ring 4 is a sleek, all-titanium smart ring designed for millennial professionals seeking precise health tracking. It monitors over 50 biometric metrics including sleep quality, stress levels, heart health, and women’s health, powered by adaptive Smart Sensing technology. With a unique sizing kit for a perfect fit and up to 8 days of battery life, it offers comfort and convenience without distractions. The ring supports multiple styles that can be switched via the app, and includes a free first month of membership for personalized health insights. Note: full data access requires a subscription.

## Description

Introducing Oura Ring 4: the latest evolution of the revolutionary smart ring. Oura Ring 4 brings you closer to what matters most — your health. The updated all-titanium design is powered by Smart Sensing, a new sensing platform that doesn’t just measure your biometrics, it adapts to you, providing insights into over 50 health metrics including sleep, readiness, activity, heart health, stress, metabolic health, and women’s health. Oura Ring quietly and comfortably monitors your health and with 5 to 8 days of battery life — you can forget it’s even on. With multi-ring support, change Oura Ring 4 styles as easily as changing your outfit. If you have two or more Oura Ring 4 styles, you can now switch easily between different finishes in the Oura App.

Review: Happily Suprised - I have had this for a week. It is supposed to track your health better over time as it learns your baseline. However, I am already blown away by this ring. I made the purchase because I have insomnia. I have tried other rings and devices to track my sleep, but they have not worked well. The Oura app is insanly accurate and intuitive. It even clocked that I had trouble breathing one night when I was congested. It can track multiple sleep episodes in one day and naps. It also tracks sleep debt which is very helpful when I am having trouble sleeping. I just had to charge it after a week and I have not taken it off except to shower (you can wear it in shower but I prefer not to get it full of conditioner). Other features have also been helpful like stress monitoring. I am frequently stressed (hence the insomnia) and the ring has clocked that and even has mini relaxing meditations to help me calm down. Literally a game changer. I have tried soooo many alternatives. But this is the one.
Review: Read this review if you are considering the Oura ring! - Let me start by saying I REALLY wanted to like this ring! I wouldn’t have spent so much money on it if I wasn’t all in! My first disappointment came from, just learning/realizing that the ring did not have the functionality that, I had understood it to have. Does it track your heart rate? Mmmmm… sort of. If you are hoping for it to track your heart rate while you are exercising, you are going to be sorely disappointed. It does heart rate readings every 10 to 30 minutes. No matter what you’re doing. That is one reading every 10 to 30 minutes… Which by the way you have no control of so it might be 10, it might be . So if you’re hoping to capture your peak heart rate while you are exercising, good luck. There is a function where you can record your workout and, I thought maybe that would be a workaround but no, all that really does is, record your path with GPS tracking to give you a visual of the route you took. And it’ll take a couple heart rate readings but, again, not at any meaningful regular interval while you are exercising. There is a manual function to check your heart rate which, has to be selected in the app and then it asks you to stay still for 30 seconds so that it can take your heart rate… And again, if you’re exercising, and you want your heart rate being tracked, you can’t stop everything and pull out your phone every few minutes to force it to take a reading. And, don’t forget, to also stop and be still so that it can take the reading.🤦‍♀️ Does it detect when you are stressed? One of the features this ring boasts is, tracking your stress. Supposedly, your body gives off particular signals when you are stressed and, the App puts a lot of focus on the amount of stress that you’ve had during your day. The problem is, it’s wildly inaccurate. It goes further to say that, eating, exercising, or doing things you enjoy can all give off those same signals as stress lol so, it’s not really a very useful metric for anything IMO. It will say I am stressed when I am eating, when I am exercising, but even when I am doing something relaxing and enjoyable like, in my garden interestingly enough, it has correctly detected a few times that I got particular news that sent my stress levels way up. It did pick those up. But, again, how useful is it if, it picks up so much of everything else as stress also 😆 I mean unless you are just a slug and lay around all day, it’s going to report that you had stress throughout the day 🤷‍♀️ And how about that subscription? Does the ring give basic metrics without the subscription? No. Big fat no. This is my biggest problem with this ring. I didn’t know if I felt like that the subscription would be valuable enough to me so I made sure before I purchased it that, if I didn’t want the extras of the subscription that the ring would still continue to track the most basic things like, step count. And, it reports that it does do that. HOWEVER, what they fail to mention is that, they don’t make that data available for you to see anywhere anymore lol and, it no longer updates Apple health or whatever other app you are integrating in with. So, it does NOTHING without the subscription. The only thing it will do is give you these silly readiness scores for your day. If it feels like you got a good nights sleep then it will give you a good readiness score for the day and a good sleep score. But you will see absolutely none of the data that went into building that score. No more steps, no more heart rate, no more anything. That’s IT. You can buy a ring for a fraction of the price that gives you all way more functionality, WITHOUT a Subscription. The way they make it sound before you purchase is that the subscription gives you a lot of extras. And I was willing to pay that if I felt like those extras were really valuable but because the data is so wildly inaccurate, I didn’t feel like it was particularly valuable what I thought I was getting as an “extra” From the subscription. Had I known it wouldn’t do the most basic thing to count steps without a subscription, and actually show them to me either in the app or by writing them to Apple health, I would have never purchased this ring. You’ve been warned! Good luck!

## Features

- ACCURATE SIZING ESSENTIAL - Oura Ring 4 uses unique sizing different from standard jewelry rings; use the Oura Ring 4 Sizing Kit to find your perfect fit before purchasing
- OURA MEMBERSHIP - First month of membership is included with purchase, for new members only. Subscription is 5.99/mo afterwards. Or opt for the annual prepaid option for 69.99. 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, and women’s health metrics. Oura Ring 4 is powered by Smart Sensing, which adapts to you — delivering accurate, continuous data, day and night
- LONG LASTING BATTERY - With up to 8 days of battery life, no screens and no vibrations, Oura Ring 4 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
- HSA/FSA ELIGIBLE - We can accept HSA or FSA funds for the following: Oura Ring, additional chargers, and shipping

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0D9WVJXZZ |
| Batteries | 1 Lithium Polymer batteries required. (included) |
| Best Sellers Rank | #149,340 in Electronics ( See Top 100 in Electronics ) #477 in Smart Rings |
| Customer Reviews | 3.8 3.8 out of 5 stars (913) |
| Date First Available | October 3, 2024 |
| Item Weight | 6.7 ounces |
| Item model number | JZ90-54144-04 |
| Manufacturer | Oura |
| Product Dimensions | 0.87 x 0.87 x 0.28 inches |

## Product Details

- **Battery Cell Composition:** Lithium Polymer
- **Brand:** OURA
- **Connectivity Technology:** Bluetooth
- **GPS:** GPS Via Smartphone
- **Model Name:** Oura Ring 4
- **Operating System:** i_os, android
- **Shape:** Round
- **Special Feature:** Activity Tracker, Cycle Tracking, Daily Workout Memory, Lightweight
- **Style:** Metallic
- **Wireless Communication Standard:** Bluetooth

## Images

![Oura Ring 4 - Black - Size 4 - Smart Ring, Sleep, Activity, Women’s Health, AI Advisor, Up to 8 Days of Battery Life, Size Before You Buy, Android & iOS Compatible - Image 1](https://m.media-amazon.com/images/I/51nCNxSwfYL.jpg)
![Oura Ring 4 - Black - Size 4 - Smart Ring, Sleep, Activity, Women’s Health, AI Advisor, Up to 8 Days of Battery Life, Size Before You Buy, Android & iOS Compatible - Image 2](https://m.media-amazon.com/images/I/51QDuTKnNyL.jpg)
![Oura Ring 4 - Black - Size 4 - Smart Ring, Sleep, Activity, Women’s Health, AI Advisor, Up to 8 Days of Battery Life, Size Before You Buy, Android & iOS Compatible - Image 3](https://m.media-amazon.com/images/I/71DVlVFg1RL.jpg)
![Oura Ring 4 - Black - Size 4 - Smart Ring, Sleep, Activity, Women’s Health, AI Advisor, Up to 8 Days of Battery Life, Size Before You Buy, Android & iOS Compatible - Image 4](https://m.media-amazon.com/images/I/713l574H8CL.jpg)
![Oura Ring 4 - Black - Size 4 - Smart Ring, Sleep, Activity, Women’s Health, AI Advisor, Up to 8 Days of Battery Life, Size Before You Buy, Android & iOS Compatible - Image 5](https://m.media-amazon.com/images/I/71NT8fo7vNL.jpg)

## Available Options

This product comes in different **Color, Size, Style** options.

## Questions & Answers

**Q: How long should my ring work between charges?**
A: Oura Ring 4 typically lasts 5-8 days on a full charge, depending on usage. Contact Oura Member Care if you have questions or concerns with battery life, and they will ensure your problem is resolved

**Q: How do I choose the right Oura Ring size?**
A: Using the Oura Ring 4 Sizing Kit, choose a finger for your ring. We recommend the index, middle or ring finger. Wear the sizer ring for 24 hours to ensure the fit is secure and comfortable over the course of your day.

**Q: What's included?**
A: Oura Ring 4, Oura Ring 4 Charger, and USB-C Cable.

**Q: How do I see my Oura Ring metrics?**
A: After activating your Oura Ring, you can choose a monthly or annual membership to unlock full access to Oura’s features, daily health and wellness metrics, and personalized guidance.

**Q: Can I use more than one ring?**
A: Oura Members can now connect more than one Oura Ring 4 to their Oura App and quickly switch between them. Note, this feature only supports wearing and syncing data from one active Oura Ring at a time.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Happily Suprised
*by A***Y on February 2, 2026*

I have had this for a week. It is supposed to track your health better over time as it learns your baseline. However, I am already blown away by this ring. I made the purchase because I have insomnia. I have tried other rings and devices to track my sleep, but they have not worked well. The Oura app is insanly accurate and intuitive. It even clocked that I had trouble breathing one night when I was congested. It can track multiple sleep episodes in one day and naps. It also tracks sleep debt which is very helpful when I am having trouble sleeping. I just had to charge it after a week and I have not taken it off except to shower (you can wear it in shower but I prefer not to get it full of conditioner). Other features have also been helpful like stress monitoring. I am frequently stressed (hence the insomnia) and the ring has clocked that and even has mini relaxing meditations to help me calm down. Literally a game changer. I have tried soooo many alternatives. But this is the one.

### ⭐ Read this review if you are considering the Oura ring!
*by K***S on June 7, 2025*

Let me start by saying I REALLY wanted to like this ring! I wouldn’t have spent so much money on it if I wasn’t all in! My first disappointment came from, just learning/realizing that the ring did not have the functionality that, I had understood it to have. Does it track your heart rate? Mmmmm… sort of. If you are hoping for it to track your heart rate while you are exercising, you are going to be sorely disappointed. It does heart rate readings every 10 to 30 minutes. No matter what you’re doing. That is one reading every 10 to 30 minutes… Which by the way you have no control of so it might be 10, it might be . So if you’re hoping to capture your peak heart rate while you are exercising, good luck. There is a function where you can record your workout and, I thought maybe that would be a workaround but no, all that really does is, record your path with GPS tracking to give you a visual of the route you took. And it’ll take a couple heart rate readings but, again, not at any meaningful regular interval while you are exercising. There is a manual function to check your heart rate which, has to be selected in the app and then it asks you to stay still for 30 seconds so that it can take your heart rate… And again, if you’re exercising, and you want your heart rate being tracked, you can’t stop everything and pull out your phone every few minutes to force it to take a reading. And, don’t forget, to also stop and be still so that it can take the reading.🤦‍♀️ Does it detect when you are stressed? One of the features this ring boasts is, tracking your stress. Supposedly, your body gives off particular signals when you are stressed and, the App puts a lot of focus on the amount of stress that you’ve had during your day. The problem is, it’s wildly inaccurate. It goes further to say that, eating, exercising, or doing things you enjoy can all give off those same signals as stress lol so, it’s not really a very useful metric for anything IMO. It will say I am stressed when I am eating, when I am exercising, but even when I am doing something relaxing and enjoyable like, in my garden interestingly enough, it has correctly detected a few times that I got particular news that sent my stress levels way up. It did pick those up. But, again, how useful is it if, it picks up so much of everything else as stress also 😆 I mean unless you are just a slug and lay around all day, it’s going to report that you had stress throughout the day 🤷‍♀️ And how about that subscription? Does the ring give basic metrics without the subscription? No. Big fat no. This is my biggest problem with this ring. I didn’t know if I felt like that the subscription would be valuable enough to me so I made sure before I purchased it that, if I didn’t want the extras of the subscription that the ring would still continue to track the most basic things like, step count. And, it reports that it does do that. HOWEVER, what they fail to mention is that, they don’t make that data available for you to see anywhere anymore lol and, it no longer updates Apple health or whatever other app you are integrating in with. So, it does NOTHING without the subscription. The only thing it will do is give you these silly readiness scores for your day. If it feels like you got a good nights sleep then it will give you a good readiness score for the day and a good sleep score. But you will see absolutely none of the data that went into building that score. No more steps, no more heart rate, no more anything. That’s IT. You can buy a ring for a fraction of the price that gives you all way more functionality, WITHOUT a Subscription. The way they make it sound before you purchase is that the subscription gives you a lot of extras. And I was willing to pay that if I felt like those extras were really valuable but because the data is so wildly inaccurate, I didn’t feel like it was particularly valuable what I thought I was getting as an “extra” From the subscription. Had I known it wouldn’t do the most basic thing to count steps without a subscription, and actually show them to me either in the app or by writing them to Apple health, I would have never purchased this ring. You’ve been warned! Good luck!

### ⭐⭐⭐⭐⭐ Rapid, efficient and friendly customer service! So refreshing...
*by J***T on January 9, 2026*

Purchased ring 11/2024. Worked very well until recently, when the battery would not keep a charge, even overnight. On a whim, I contacted customer support via an online chat. Diagnostics on my ring indicated a battery issue. Even though it's out of warranty, they are replacing it at no cost. Couldn't be more impressed by the rapid response and very user-friendly interaction.

## Frequently Bought Together

- Oura Ring 4 - Black - Size 4 - Smart Ring - Size First with Oura Ring 4 Sizing Kit - Sleep Tracking Wearable - Heart Rate - Fitness Tracker - Up to 8 Days of Battery Life
- 6 Pack Ring Cover Compatible with Oura Ring Gen 4/Oura Ring Gen 3 Horizon/Gen 3 Heritage, Surport Charging with Cover on, Anti-Scratch Elastic Silicone Ring Protector for Men Women Working Out Gym
- 10 Pack Ring Cover Compatible with Oura Ring Gen 4/Oura Ring Gen 3 Horizon/Gen 3 Heritage, Surport Charging with Cover on, Anti-Scratch Elastic Silicone Ring Protector for Men Women Working Out Gym

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*Product available on Desertcart Brazil*
*Store origin: BR*
*Last updated: 2026-07-26*