Brynk R3 – Smart Ring with Sleep, Heart Rate & Cycle Tracking

Name: Brynk R3 – Smart Ring with Sleep, Heart Rate & Cycle Tracking
Rating: 4.81 (21 reviews)

$89.99 $119.99

★★★★★ 4.8 · 21 reviews

4.8 21 reviewsRead reviews

Sleep, heart rate, blood oxygen automatic, even at night
Cycle and activity period calendar, steps, sport modes
Free app no subscription, nothing to unlock
Charging case included recharges the ring on the go
Lightweight, no display barely noticeable at night
IP68 handwashing and showers are no problem

Color Obsidian Black

The gallery image changes with the color. The charging case is black for all colors.

Color Obsidian Black Platinum Silver Champagne Gold Rose Quartz Pink Sapphire Blue Amethyst Purple Ruby Red

Size US 7 (EU 54) US 8 (EU 57) US 9 (EU 60) US 10 (EU 62) US 11 (EU 65) US 12 (EU 67) US 13 (EU 70)

VersionWith charging case

Your size in one minute

Free and instant – measure right here, no printer needed.

Wrap a strip of paper snugly but comfortably around your finger – ideally in the evening.
Mark the spot where it overlaps.
Measure up to the mark and enter the length here:

mm

Size chart

Size	Circumference	Inner Ø
US 7 (EU 54)	approx. 54.3 mm	17.3 mm
US 8 (EU 57)	approx. 56.9 mm	18.1 mm
US 9 (EU 60)	approx. 59.7 mm	19.0 mm
US 10 (EU 62)	approx. 62.2 mm	19.8 mm
US 11 (EU 65)	approx. 64.7 mm	20.6 mm
US 12 (EU 67)	approx. 67.2 mm	21.4 mm
US 13 (EU 70)	approx. 69.7 mm	22.2 mm

US size first, EU size (inner circumference in mm) in brackets. Between two sizes? Choose the larger one. Printable ring sizer (PDF)

New ring if you lose weight – no time limit. If you lose weight and the ring no longer fits, we'll send you the right smaller size once, free of charge. You keep the old ring. Applies only to weight loss, not to a wrongly chosen size. How it works

Add a protective cover? Matches your ring size

Tap and choose your ring's size – the cover is added when you click “Add to cart” and ships separately.

Free shipping · Delivery in 7–14 business days

Based in Austria
Support in EnglishWe usually reply within 24 h

Secure payment

A ring instead of a watch: the Brynk R3 tracks your sleep, heart rate and blood oxygen, counts your steps and logs your cycle in the calendar – no display and no subscription.

Sleep, heart rate and blood oxygen automatically, even at night
Cycle and activity: period calendar, steps, distance, calories and sport modes
Free app for iOS and Android – no subscription, nothing to unlock
Charging case included: 3–5 days per charge, and the case recharges the ring on the go
IP68, approx. 4 g, 7 colors
Sizes US 7 to 13 (EU 54 to 70): the EU size equals the inner circumference in millimeters; between two sizes, choose the larger one. Printable ring sizer

In the box: ring in your color and size, black charging case with built-in battery, charging cable, instructions.

Shipping: free on orders over $100, otherwise from $5.90 depending on your country. Delivery in 7–14 business days (up to 20 in remote regions).

3–5 daysBattery per charge
approx. 4 gWeight, depending on size
7 colors7 sizes, US 7 to 13

Real customer photos

What buyers say about the Brynk R3

4.8 21 reviews · read all ›

★★★★★
Arrived almost fully charged
I'm really thrilled – the first time, I hadn't measured properly and couldn't wear it. Now I don't find it uncomfortable at all, and it looks really good. I'll keep watching the readings to see how reliable they are. It arrived almost fully charged, so I could put it on right away. My advice: measure your finger really carefully, and the size will fit perfectly.

Anonymous · April 2026
★★★★★
Prettier than expected
Prettier than expected. The app, which is very easy to use, shows your heart rate, blood oxygen and sleep quality. Instructions for downloading the app were included. The charging case is stylish and practical. Wearing it all day, I charge it every two to three days. It connects via Bluetooth and works even when other Bluetooth devices are connected at the same time.

a***r · November 2025
★★★★★
Fits perfectly
I really like it! About the size: I ordered on a hunch, and it fits exactly – my fingers are fairly slim, and it sits well. For the price, it's ideal for finding out whether a smart ring is for you.

G***o · March 2026
★★★★★
Very happy with purple
I'd wanted a ring like this for a long time, but the well-known models were too expensive for me. So I ordered this one and went with purple. Time will tell whether the color lasts – for now, I'm very happy.

L***a · August 2026
★★★★★
Finally an overview of my sleep
Highly recommended for anyone who wants to keep an eye on their sleep habits. I now know how much I really sleep at night. And it counts my steps at work too – every day is different for me.

Anonymous · January 2026
★★★★★
Fits perfectly – measure properly first
Great so far! Don't rely on the size chart alone – it's better to measure with a ring sizer. My finger is a size 10, and the ring in size 10 fits perfectly.

a***a · November 2025
★★★★★
Exactly as described, beautiful ring
Exactly as described. The tracking is good, the settings are good, there are no ads in the app – and it's pretty, too. I just don't know if it's waterproof, so I take it off every time I shower.

a***r · April 2026
★★★★★
Does everything I wanted
I love this ring. It does everything I wanted: it measures sleep quality, syncs with my phone without any problems and counts steps and movement during workouts. Heart rate and blood oxygen are tracked too. My tip: if you want to track your sleep, go one size up – fingers swell at night. I can really recommend this ring.

C***e · October 2025

On video

Charging case, sensors, water resistance

The ring sits in its charging case, the sensors are on the inside, and you trigger your phone camera with a finger gesture.

Choose color and size

Inside the ring

What's inside the Brynk R3

Sensors, battery and housing – that's all it takes to track sleep, heart rate and activity.

Heart rate & SpO2
Optical sensor
Measures heart rate and blood oxygen on the inside – even at night.
Sleep & steps
Motion sensor
Detects steps, activity and sleep stages.
With battery
Charging case included
The case has a built-in battery and recharges the ring several times on the go.
IP68
Water resistance
Handwashing, showers and rain are no problem. Not for sauna, salt water or diving.
Photo
Camera shutter
Trigger your phone camera with a finger gesture – handy for group photos.
Metal
Lightweight metal housing
Aluminum alloy outside, epoxy resin inside, approx. 4 g.

The app

Everything in one free app

Pair the ring and you're done. Then just take a quick look each morning – with day, week and month trends.

Free app

Overview

All your data in one view – no subscription

Sleep

Every night

Score, duration and deep, light and REM sleep

Heart rate

Automatic

Heart rate at your chosen interval, resting heart rate over time

Blood oxygen

SpO2

Automatically at night or on demand

Activity

Every day

Steps, distance and calories with a daily goal

Cycle

Calendar

Log your period, see your history in the calendar

Sport modes

Workouts

Running, cycling, yoga, strength training and more

My ring

Settings

Battery level, measurement interval, photos with a finger gesture

Illustration of the app features; the view may vary slightly depending on the version. For fitness and wellness, not a medical device.

How it works

Ready in three steps

Charge
Place the ring in the charging case – it snaps magnetically onto the charging spot – and charge the case with the cable. The ring is fully charged in about one to two hours.
Pair the app
Download the free app – the QR code is in the quick guide – and connect the ring via Bluetooth.
Wear and check
Wear it on your index or middle finger. In the morning, you'll see your sleep, heart rate and blood oxygen from the night.

Your phone doesn't need to be nearby all the time – the ring stores your data and syncs it later.

What you get out of it

From day one to daily habit

What buyers report after a few weeks: they know their sleep and their resting heart rate.

Day 1 Ring on, app open Pairing takes a minute. In the evening, you'll see the day's steps, heart rate and blood oxygen.
Night 1 Your first night is logged When you fell asleep, deep sleep, REM, wake-ups – with nothing on your wrist to bother you.
Week 1 Patterns emerge How a late coffee, a glass of wine or a workout changes your night.
Weeks 2–3 Resting heart rate over time Your resting heart rate shows up in the weekly trend, and your cycle is tracked in the calendar.
Month 1 and beyond The ring becomes a habit Charge it every 3–5 days; otherwise you forget it's there – and take a quick look at the app each morning.

The readings are intended for fitness and wellness and do not replace a medical examination.

Brynk R3 size chart: sizes US 7 to 13 (EU 54 to 70) with inner diameter and circumference

Find your size

Your size in two minutes

US size first, EU size in brackets. The EU size roughly equals the inner circumference in millimeters – for the most accurate result, use the printable ring sizer.

Paper stripwrap it around your finger, mark the overlap, read the length in mm
Circlesplace a well-fitting ring on top and compare
Between two sizeschoose the larger one
Measure in the afternoonfingers swell in the evening and in warm weather

Print ring sizer

Comparison

What sets the Brynk R3 apart

Sleep, heart rate, blood oxygen, cycle and activity – with a free app, no subscription and nothing to unlock.

Compared with brand-name rings

Brynk R3 Brand-name rings

App free, no subscription some only fully usable with a monthly subscription

Sleep stages deep, light, REM yes

Heart rate & blood oxygen automatic, even at night yes

Cycle tracking in the app usually yes

Charging case always included, with built-in battery usually included

Ring too big after weight loss one free new ring, no time limit buy a new one

Colors 7 to choose from often 2 to 4

Sizes 7 (US 7 to 13; EU 54 to 70) usually 7 to 8

Shipping free, 7–14 business days shipping costs vary by retailer

Support in English, reply within 24 h often chat only

Popular models on the market as of September 2026 – deliberately without brand names, since features and subscriptions change all the time.

Smartwatch or smart ring?

Smart Ring Smartwatch

At night barely noticeable bothers many people on the wrist

Charging every 3–5 days often daily

Distraction no display, no pop-ups display and notifications

Look looks like a ring visible tech

During workouts no band to chafe stats right on the display

Both measure similar things – the difference is how it feels in everyday life.

In the box

What's in the box

Unpack, charge, pair the app – done.

1× Brynk R3in your color and size
1× Charging caseblack, with built-in battery
1× Charging cablefor the charging case
1× Quick guidewith QR code for the free app

Power adapter not included.

Accessories

Protective cover for your R3

Soft silicone for the outside: the cover protects the ring from scratches during workouts or at work, while the sensors on the inside stay uncovered. Choose the size that matches your ring.

Remove the cover for charging. It ships separately and may arrive a few days after the ring.

Full details on the cover

Gift idea

A gift that gets used every day

Comes in a charging case: unpack, charge, done. Not sure of the size? Send them the ring sizer. If the ring gets too big after weight loss, they get the smaller size once for free.

For her

Sleep, cycle and everyday life

Rose Quartz, Champagne or Amethyst – subtle enough for the office and at night.

For him

Stats without a watch on your wrist

Obsidian, Platinum or Sapphire. Nothing pinches during workouts or at night.

Specifications

Tech specs

Model: Brynk R3 Smart Ring
Housing: metal (aluminum alloy), epoxy resin inside
Colors: Obsidian, Platinum, Champagne, Rose Quartz, Sapphire, Amethyst, Ruby
Sizes: US 7 to 13 (EU 54 to 70), inner Ø 17.3 to 22.2 mm
Weight and dimensions: approx. 4 g depending on size · approx. 8 mm wide · approx. 2.5 mm thick
Sensors: optical heart rate and SpO2 sensor (PPG), motion sensor
Metrics: sleep stages, heart rate, blood oxygen, steps, distance, calories, sport modes, cycle (logged in the app)
Battery: 3 to 5 days per charge, fully charged in approx. 1–2 hours; the charging case has a built-in battery and recharges the ring several times
Connectivity: Bluetooth, app for iOS and Android – free, no subscription
Water resistance: IP68 – handwashing and showers; not for sauna, salt water, diving
Partner set: two rings, both with charging case, at a set price
In the box: ring, charging case (black, with built-in battery), charging cable, quick guide
Weight-loss size guarantee: new ring in a smaller size – once, free, no time limit; applies only to weight loss, not to a wrongly chosen size
Shipping: free, delivery in 7–14 business days
Seller in the EU: Flynk Tech, Austria (operator of Brynk) – address and contact details in our legal notice

The readings are intended for fitness and wellness and do not replace a medical examination. For questions about safety, the battery or disposal, please use our contact form.

Questions about the ring

Frequently asked questions

Size, guarantee, battery, app and shipping – quick answers.

Ask a question

I'm between two sizes – which one should I choose?

The larger one. A ring with a little room measures more reliably than one that's tight – and fingers swell over the course of the day and in warm weather.

What if I lose weight and the ring no longer fits?

Then you get a new ring in the smaller size for free, once per ring purchased – with no time limit. You keep the old ring. Email support@brynkshop.com with your order number and new size. This applies only to weight loss, not to a wrongly chosen size. Full details

Which finger should I wear the ring on?

Ideally on the index or middle finger of the hand you use less. The sensor stays steadier there and the readings are more stable. On the thumb, the ring is less accurate.

How long does the battery last?

3 to 5 days, depending on use. If the ring measures heart rate and blood oxygen at the shortest interval, it's less. The charging case has a built-in battery and recharges the ring several times on the go.

Does the ring work with my phone?

Yes, with iPhones and Android phones via Bluetooth – any operating system from the last few years will do. You'll find the app via the QR code in the quick guide. Your phone doesn't need to be with you all the time: the ring stores your data and syncs it as soon as you open the app.

Can I work out with the ring?

Yes, the app has modes for running, cycling, yoga, strength training and more. For lifting weights, climbing or bouldering, it's best to take it off – metal on metal causes scratches.

How does cycle tracking work?

You log your period in the app and see your history in the calendar, alongside your sleep and resting heart rate. There's no body-temperature measurement.

How accurate are the readings?

The ring measures optically on your finger. For trends – are you sleeping better, has your resting heart rate dropped – that's very useful. It's not designed as a medical device and doesn't replace a visit to the doctor.

Can I order two rings together?

Yes – with the partner set, you get two rings with charging case at a set price below two single rings. Mix and match colors and sizes as you like; the discount is applied automatically in your cart. Just choose “2 rings – partner set” above.

When will my ring arrive?

Your ring usually arrives within 7–14 business days. Shipping is free, and you'll get a tracking number by email. You'll find the seller's name and address in our legal notice.

5 stars: 17 (81%)
4 stars: 4 (19%)
3 stars: 0 (0%)
2 stars: 0 (0%)
1 star: 0 (0%)

Very happy with purple

I'd wanted a ring like this for a long time, but the well-known models were too expensive for me. So I ordered this one and went with purple. Time will tell whether the color lasts – for now, I'm very happy.

Very nice

Very nice. The battery is lasting well so far – I'll post an update.

Everything works

Perfect, everything works.

Does the job

Quite chunky. The charging case had a few light scratches. It does the job – let's see how it holds up over time.

Comfortable to wear

Very good product, one of my best purchases. It's easy to wear, tracks sleep well, doesn't get in the way – and it looks good, too.

Better to go one size smaller

Please add a note that you should order one size smaller.

Easy to connect

I got the set with the charging case. Easy to connect and pretty accurate.

Good battery life

Good battery life, fits well, no connection problems.

Exactly as described, beautiful ring

Exactly as described. The tracking is good, the settings are good, there are no ads in the app – and it's pretty, too. I just don't know if it's waterproof, so I take it off every time I shower.

Arrived almost fully charged

I'm really thrilled – the first time, I hadn't measured properly and couldn't wear it. Now I don't find it uncomfortable at all, and it looks really good. I'll keep watching the readings to see how reliable they are. It arrived almost fully charged, so I could put it on right away. My advice: measure your finger really carefully, and the size will fit perfectly.

Fits perfectly

I really like it! About the size: I ordered on a hunch, and it fits exactly – my fingers are fairly slim, and it sits well. For the price, it's ideal for finding out whether a smart ring is for you.

Very happy for the price

For the price I paid, I'm very happy. It does its job: sleep, heart rate and blood oxygen. Of course these readings can't be 100% reliable, but overall they're about right. My only criticism is that sleep is only tracked at night – naps aren't recorded. Otherwise, nice design and good materials. I went with size 12; it's a few millimeters bigger, but still perfectly wearable.

Finally an overview of my sleep

Highly recommended for anyone who wants to keep an eye on their sleep habits. I now know how much I really sleep at night. And it counts my steps at work too – every day is different for me.

Great ring

Great ring. The app is good, and it connected quickly. Recommended!

Ring very good, app sometimes slow

Fast delivery and a good product. The ring fits well and works wonderfully. Only the app is a bit slow at times, and syncing sometimes takes a while. I also think it's a shame that the measuring interval can only be shortened from 30 to 15 minutes – 10 minutes would be better. But you can live with that. The ring itself is very good and measures heart rate and blood oxygen. I'm very happy and can recommend it 😍👍

Prettier than expected

Prettier than expected. The app, which is very easy to use, shows your heart rate, blood oxygen and sleep quality. Instructions for downloading the app were included. The charging case is stylish and practical. Wearing it all day, I charge it every two to three days. It connects via Bluetooth and works even when other Bluetooth devices are connected at the same time.

Exactly as described

Just arrived and already tried it out. It's exactly as described. Excellent value for money. Recommended.

Tip for the right size

Great. I found that it's best to measure your hand right after waking up – that way you'll find the right size.

Fits perfectly – measure properly first

Great so far! Don't rely on the size chart alone – it's better to measure with a ring sizer. My finger is a size 10, and the ring in size 10 fits perfectly.