---
product_id: 710378271
title: "Oura Ring 4 - Black - Size 8 | Smart Ring Sizing Kit | Sleep Tracking Wearable - Heart Rate - Fitness Tracker - Up to 8 Days Battery Life"
brand: "oura"
price: "3875 zł"
currency: PLN
in_stock: true
reviews_count: 12
category: "Oura"
url: https://www.desertcart.pl/products/710378271-oura-ring-4-black-size-8-smart-ring-sizing-kit
store_origin: PL
region: Poland
---

# 8 days battery life 100m water resistant 80 min wireless charge Oura Ring 4 - Black - Size 8 | Smart Ring Sizing Kit | Sleep Tracking Wearable - Heart Rate - Fitness Tracker - Up to 8 Days Battery Life

**Brand:** oura
**Price:** 3875 zł
**Availability:** ✅ In Stock

## Summary

> 💍 Elevate your health game with the ring that works as hard as you do.

## Quick Answers

- **What is this?** Oura Ring 4 - Black - Size 8 | Smart Ring Sizing Kit | Sleep Tracking Wearable - Heart Rate - Fitness Tracker - Up to 8 Days Battery Life by oura
- **How much does it cost?** 3875 zł with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.pl](https://www.desertcart.pl/products/710378271-oura-ring-4-black-size-8-smart-ring-sizing-kit)

## 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

- • **Deep Health Insights:** Track heart rate, sleep quality, and activity with precision to optimize your wellness.
- • **Waterproof Confidence:** Dive into life worry-free with 100m water resistance built for every adventure.
- • **Effortless All-Day Wear:** Sleek titanium design ensures comfort and durability for your busiest days.
- • **Seamless Smartphone Sync:** Instant Bluetooth connectivity delivers real-time health analytics right to your app.
- • **Unmatched Battery Endurance:** Up to 8 days of power with quick 80-minute wireless charging—stay unplugged longer.

## Overview

The Oura Ring 4 is a cutting-edge smart ring crafted from durable titanium, designed for adults seeking discreet yet powerful health tracking. It monitors heart rate, sleep patterns, and activity levels with advanced sensors, syncing seamlessly via Bluetooth to your smartphone app. Boasting up to 8 days of battery life and 100m water resistance, it combines style, comfort, and robust functionality in a compact wearable.

## Description

Free delivery and returns on eligible orders. Buy Oura Ring 4 - Black - Size 8 | Smart Ring Sizing Kit | Sleep Tracking Wearable - Heart Rate - Fitness Tracker - Up to 8 Days Battery Life at desertcart UK.

Review: A great alternative to a smart-watch - I was keen to utilise technology to help with my fitness, but love mechanical watches so a smart-watch wasn't an option. Came across this and after some research I gave it a punt. Very happy customer, the ring is a doddle to set up and works a treat. Battery life is a snadge less than advertised but not enough to make me dock points. It's a shame about the subscription, as I think the ring is costly enough that it's something of a liberty to charge for ongoing use, they could lose things like the guided meditation etc and give a free option, or bake in more value-add to the app. Enough moaning though, what it does it does really well, giving me insights into my sleep patterns and broader health. I am happy I bought it and check the app at least daily months after buying.
Review: So So Happy! - I hesitated for a while before investing in this gadget. And I love my Gadgets! but after doing some homework on the competition, I decided to jump for it. First, the fit and metal colour are great, I couldn't be happier, the quality and durability is insane, i do everything with it, I rarely take it off. The connectivity to my Samsung Z Fold6 was flawless, no hiccups, plus, everything you open the app, it updates in no time. so great compatibility. Now, you need to give it time to gather data about you, of course... it will not happen overnight which is quite right, but the intel you get afterwards is great. Your body age, sleep quality, energy available, your stress, it is such a great little ring. it is a lot of money for such a small device but the value for money is worth it. I highly recommend it if you are curious and want to be nudge in the right direction for better health.

## Features

- Compact and intelligent design for comfortable everyday wear
- Advanced health monitoring capabilities, including heart rate, sleep patterns, and activity tracking
- Long battery life with convenient wireless charging
- Seamless smartphone app integration for detailed health and activity analytics
- Available in multiple finishes and sizes for personalized style

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0D9WVR866 |
| Age Range Description | Adult |
| Band Colour | Black |
| Band Material Type | Titanium |
| Battery Average Life | 8 days |
| Battery Cell Type | Lithium Polymer |
| Battery Charge Time | 80 minutes |
| Best Sellers Rank | 279 in Electronics & Photo ( See Top 100 in Electronics & Photo ) 1 in Wearable Tech Rings |
| Box Contents | Information Booklet, Oura Ring 4, Oura Ring 4 Charger, Quick Start Guide, USB-C Cable |
| Brand Name | OURA |
| Case Material Type | Titanium |
| Closure Type | Continuous Band |
| Colour | Black |
| Communication Feature | Bluetooth |
| Compatible Devices | Smartphone, Tablet |
| Compatible Phone Models | Smartphone |
| Connectivity Technology | Bluetooth, Wi-Fi, Proprietary Wireless Protocol |
| Controller Type | Ring |
| Customer Reviews | 4.3 4.3 out of 5 stars (6,230) |
| Display Type | No Display |
| GPS Geotagging Functionality | No GPS |
| Global Trade Identification Number | 06430060153165 |
| Human Interface Input | Unknown |
| Item Dimensions | 25 x 25 x 7 millimetres |
| Item Dimensions D x W x H | 25D x 25W x 7H millimetres |
| Manufacturer | Oura |
| Metrics Measured | [MULTI] |
| Model Name | Oura Ring 4 - Black - Size 8 |
| Model Number | JZ90-54144-08 |
| Operating System | Proprietary Operating System |
| Product Features | Activity Tracker |
| Shape | Ring |
| Style Name | Modern |
| Supported Application | Fitness Tracker |
| Supported Satellite Navigation System | GPS |
| Target Audience | Unisex Adults |
| Warranty Type | Lifetime |
| Water Resistance Depth | 100 Metres |
| Water Resistance Level | Water Resistant |
| Wearable Computer Type | Smart Ring |
| Wireless Compability | Bluetooth |

## Product Details

- **Battery cell composition:** Lithium Polymer
- **Brand:** OURA
- **Connectivity technology:** Bluetooth, Wi-Fi, Proprietary Wireless Protocol
- **GPS:** No GPS
- **Model name:** Oura Ring 4 - Black - Size 8
- **Operating system:** Proprietary Operating System
- **Shape:** Ring
- **Special feature:** Activity Tracker
- **Style:** Modern
- **Wireless communication standard:** Bluetooth

## Images

![Oura Ring 4 - Black - Size 8 | Smart Ring Sizing Kit | Sleep Tracking Wearable - Heart Rate - Fitness Tracker - Up to 8 Days Battery Life - Image 1](https://m.media-amazon.com/images/I/513EeiCr+QL.jpg)
![Oura Ring 4 - Black - Size 8 | Smart Ring Sizing Kit | Sleep Tracking Wearable - Heart Rate - Fitness Tracker - Up to 8 Days Battery Life - Image 2](https://m.media-amazon.com/images/I/51f7Md52AIL.jpg)
![Oura Ring 4 - Black - Size 8 | Smart Ring Sizing Kit | Sleep Tracking Wearable - Heart Rate - Fitness Tracker - Up to 8 Days Battery Life - Image 3](https://m.media-amazon.com/images/I/71jVxf3HxrL.jpg)
![Oura Ring 4 - Black - Size 8 | Smart Ring Sizing Kit | Sleep Tracking Wearable - Heart Rate - Fitness Tracker - Up to 8 Days Battery Life - Image 4](https://m.media-amazon.com/images/I/613EYvr-lAL.jpg)
![Oura Ring 4 - Black - Size 8 | Smart Ring Sizing Kit | Sleep Tracking Wearable - Heart Rate - Fitness Tracker - Up to 8 Days Battery Life - Image 5](https://m.media-amazon.com/images/I/61FFomT0clL.jpg)

## Available Options

This product comes in different **Color, Size** 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

### ⭐⭐⭐⭐⭐ A great alternative to a smart-watch
*by S***Y on 16 June 2025*

I was keen to utilise technology to help with my fitness, but love mechanical watches so a smart-watch wasn't an option. Came across this and after some research I gave it a punt. Very happy customer, the ring is a doddle to set up and works a treat. Battery life is a snadge less than advertised but not enough to make me dock points. It's a shame about the subscription, as I think the ring is costly enough that it's something of a liberty to charge for ongoing use, they could lose things like the guided meditation etc and give a free option, or bake in more value-add to the app. Enough moaning though, what it does it does really well, giving me insights into my sleep patterns and broader health. I am happy I bought it and check the app at least daily months after buying.

### ⭐⭐⭐⭐⭐ So So Happy!
*by M***D on 18 October 2025*

I hesitated for a while before investing in this gadget. And I love my Gadgets! but after doing some homework on the competition, I decided to jump for it. First, the fit and metal colour are great, I couldn't be happier, the quality and durability is insane, i do everything with it, I rarely take it off. The connectivity to my Samsung Z Fold6 was flawless, no hiccups, plus, everything you open the app, it updates in no time. so great compatibility. Now, you need to give it time to gather data about you, of course... it will not happen overnight which is quite right, but the intel you get afterwards is great. Your body age, sleep quality, energy available, your stress, it is such a great little ring. it is a lot of money for such a small device but the value for money is worth it. I highly recommend it if you are curious and want to be nudge in the right direction for better health.

### ⭐⭐⭐⭐⭐ A great tool which does exactly what it says.
*by T***P on 12 December 2025*

The app is brilliant. It takes a while to get to know you, so don't expect instant insights, but as it builds a picture it is really good at telling you what's going on. I am using it to track my food etc as well, so not exclusively related to what's happening on the ring. On the ring specifically? Well, it is chunkier than a ring you'd buy as jewellery. That's ok and it's not ridiculous, but you have to get used to it. I do find I take it off and put it on more, or change fingers, as my hand needs a rest. The colour... Despite the name stealth, does stand out. If you want something more subtle then brushed or silver is probably better, as it's more like typical jewellery. That being said, I've gotten used to it. Sizing - definitely get the sizing kit and wear not for a few mins but for a day or two to understand how your fingers change size. Battery life is good. I reckon 8 charge it once every 4 otlr 5 days so far. I understand turning off blood oxygen measuring is the way to really eek out more battery life. You can also use airplane mode to reduce how often it speaks to your phone. But yeah, no regrets, it's a great tool and honestly, easier to live with than a smart watch.

## Frequently Bought Together

- Oura Ring 4 - Black - Size 8 - Smart Ring - Size First with Oura Ring 4 Sizing Kit - Sleep Tracking Wearable - Heart Rate - Fitness Tracker - Up to 8 Days of Battery Life
- sylacor Ring Cover for Oura Ring Gen 4/ Gen 3, Anti-Scratch Elastic Silicone Oura Ring Case Protector for Men Women Working Out Gym

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---

*Product available on Desertcart Poland*
*Store origin: PL*
*Last updated: 2026-03-20*