What's Improved in Muse Ring One Gen 2 vs Gen 1?

Ring One Gen-2 is the most substantial update we've made since the ring first launched — not one change, but dozens of them, spanning the metal the ring is built from, the case that charges it, and the algorithms that turn raw sensor data into metrics you can actually trust. This is a closer look at what changed, why, and what it means for you as an existing owner.

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Ring Hardware

Comfort was the single goal behind every hardware decision in Gen-2. We wanted a ring you could put on and simply forget about — no daily adjustment, no awareness of it on your hand, just the quiet feeling of wearing nothing at all while it does its job. Getting there meant a harder engineering problem than shrinking a spec sheet: miniaturizing the ring's internal metal components without giving up an ounce of durability, so comfort and toughness could improve together.

Gen-2's hardware improvements are built around three goals: a slimmer, lighter overall feel, a softer touch against your skin through a full day of wear, and a ring you can confidently keep on through washing up, workouts, and showers. Here's how we got there.

1. Slimmer by Design, Down to the Metal

Making Ring One thinner without compromising anything inside it meant redesigning at the component level, not just filing down the outer shell. Every internal metal part — the structural elements that give the ring its strength — went through a miniaturization process focused on one goal: take up less space without giving up an ounce of durability.

The result is a ring that's roughly 10% thinner overall, while holding the same structural integrity Ring One is built on. That thinner profile is what makes the ring easy to slip on in the morning — and easy to stop noticing by mid-morning.

What's different

Getting thinner without losing durability meant shrinking the metal components themselves, not just the outer shell. That's a harder engineering problem to solve — and it's why Gen-2 delivers a meaningfully slimmer ring while keeping the strength Ring One is built on.

2. Rounder Everywhere It Touches You

Comfort comes down to curves. Gen-2's endcap curvature is now 2x more rounded, and the inner-band (ID) — the surface that sits directly against your finger — is 4x more rounded. Every point of contact has been softened and reshaped.

The effect shows up in the moments that matter most: an even, gentle feel over a full day of wear, and easy movement through everyday routines like washing your face, bathing, or working out. Rounder isn't just a design choice here — it's what makes an always-on ring feel like it's barely there.

What's different

We reshaped every point of contact — endcap and inner band alike — around real everyday moments: workouts, washing up, long days at a desk. The goal wasn't a rounder ring for its own sake — it was a ring built to stay comfortable through all of it, one you never have to think about taking off.

3. A Coating Built in Three Stages, Not One

Durability claims are easy to make and hard to earn. Gen-2's "up to 3x more durable" coating comes from treating the coating as a three-stage process instead of a single step.

Before any coating goes on, the ring surface goes through an added pre-processing stage — a finer surface preparation designed to give the coating something to truly key into, rather than simply sit on top of it. That matters as much as the coating formula itself: durability comes from adhesion as much as hardness, and a coating that's properly bonded to the metal underneath holds its ground far better over time.

The coating composition has also been changed, refining the underlying chemistry to hold up better under real-world contact. A post-processing step then locks that structure firmly in place, giving the surface a tight, consistent finish from edge to edge.

Pre-treatment, new composition, post-treatment — three levers instead of one, which is how you get a multiple, not a marginal gain.

That 3x durability gain covers the two things that actually wear a ring down: metal-to-metal contact — dumbbells and gym equipment, knocks against your phone or laptop, everyday taps on a table or countertop — and environmental exposure, from sweat to shifts in humidity and temperature. Gen-2's coating was built to hold up against both at once.

Did you know?

Coating durability comes down to adhesion as much as hardness. Gen-2's pre- and post-processing steps are designed specifically to strengthen that bond, so the coating performs as one integrated layer with the metal beneath it — not just a surface treatment sitting on top.

What's different

Most rings treat coating as a single spray-and-done step. Gen-2 treats it as a process — prepare the surface, refine the chemistry, then lock it in — which is where the 3x durability gain actually comes from.

4. Sealed Against Sweat, Chemicals, and Everyday Heat Cycling

Everything that makes a smart ring useful — the battery, the sensors, the board — lives inside a sealed cavity, protected by epoxy potting. Day-to-day life brings a lot to that seal: sweat and moisture from workouts and humid days, everyday chemical contact from soap, lotion, and hand sanitizer, and constant thermal cycling as the ring moves between a cold morning, a hot shower, and body heat.

Gen-2's epoxy potting was engineered to hold up against all three together. The formulation and seal were strengthened as a pair, so the ring stays reliably protected through sweat, chemical exposure, and temperature swings — the real, combined conditions of wearing a ring that never comes off.

What's different

Gen-2's potting was engineered around the real, combined conditions of nonstop wear — sweat, chemical contact, and temperature swings happening together, not one at a time. That's the difference between protection built for a lab test and protection built for your actual day.

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Case Hardware

The charging case works quietly in the background — you drop the ring in, walk away, and expect it to just work. That simplicity depends on what's happening underneath: how the board handles everyday electrical noise, how solidly the case itself is built, and how efficiently it manages heat while charging. Gen-2's case was refined on all three fronts.

1. A Board Built to Handle Static and Interference

Electrical noise doesn't always come from something dramatic — it can come from a nearby device, a faulty charger, an airport security scanner, or any number of everyday electrical anomalies the case is exposed to. Gen-2 addresses this at the source rather than patching around it.

The case now has stronger ESD and EMI protection, but the bigger change is underneath that: a revised PCB layout and a refined surface-mount assembly process, so the board itself is sturdier by design, not just shielded after the fact.

Did you know?

Static discharge and electromagnetic interference can come from almost anywhere — a nearby phone or charger, a faulty power adapter, airport security scanners, or stray fields from other electronics close by. Designing the board layout to handle that whole range of sources matters more than adding protection as an afterthought.

What's different

Gen-2's board improvements start at the layout and assembly process itself, not just with added protection components. That's what makes the durability gain structural, not cosmetic.

2. A More Premium Case, Inside and Out

The case moves to a new plastic material with a noticeably more premium texture and finish — the kind of surface feel you notice the moment you pick it up. Several internal parts were also revised to tighten air gaps and alignment between components, so the case closes, sits, and feels more solidly built end to end.

The result is a case that looks and feels as considered as the ring it carries.

What's different

Gen-2's case pairs a new material with tighter internal tolerances, giving it the fit, finish, and solidity of a premium accessory rather than just a charging box.

3. Cooler Charging, By Design

Charging generates heat, and heat is the quiet enemy of both comfort and long-term battery health. Gen-2's case was redesigned internally with better thermal management, keeping the ring's charging cycle noticeably cooler throughout.

What's different

Gen-2's internal thermal design keeps charging temperatures noticeably lower — the same charging cycle, just cooler to the touch throughout.

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Algorithms & Health Metrics

Parts 1 and 2 were about how Ring One feels and holds up physically. Part 3 is about what it's actually measuring underneath — heart rate, HRV, blood pressure, temperature — and how reliably it gets those readings right, especially in the moments that matter most: mid-workout, first thing in the morning, or anywhere your signal is hardest to read.

1. Exercise Heart Rate You Can Actually Trust Mid-Workout

Gen-1 estimated heart rate using one of its two PPG sensors at a time. That works well at rest, but the moment a workout gets intense — sweat building up, the ring shifting slightly, quick changes in motion — a single sensor can momentarily lose a clean signal.

Gen-2 fuses both PPG sensors into a single hybrid signal, so a momentary drop on one is covered by the other instead of interrupting the reading. That signal is then cleaned up further using motion data from the onboard accelerometer (IMU), which compensates for motion-related artifacts in real time. On top of both, a more advanced signal-quality check (SQI) qualifies the signal specifically for high-intensity activity, so the ring knows when to trust a reading and tunes its sensor parameters accordingly.

Sensor fusion, motion compensation, and smarter signal-quality checks together give Gen-2 meaningfully stronger exercise heart rate performance during high-intensity workouts compared to Gen-1.

Did you know?

A PPG sensor works by shining light into your skin and measuring how blood flow changes the light that bounces back. If that light path is disrupted — even briefly, from sweat, motion, or a slight shift in angle — a single sensor can lose the signal entirely. Fusing two independent PPG channels means one can effectively cover for the other.

What's different

Gen-1 read heart rate from one PPG channel at a time. Gen-2 fuses both channels with motion data, so a brief dropout on one sensor no longer interrupts the reading — the case that matters most during high-intensity exercise, exactly when signal noise is highest.

2. HRV Accuracy Without the Battery Trade-off

HRV (heart rate variability) is one of the more meaningful markers of stress and cardiovascular fitness a wearable can track. The challenge is that most wearables improve HRV accuracy the same way: sample more often, or upsample more aggressively — both of which quietly cost battery life.

Gen-2's HRV algorithm was built specifically to avoid that trade-off. Rather than reaching for a higher sampling rate or heavy upsampling, it's tuned to extract more signal fidelity from the same sampling budget — giving you the best possible HRV reading without asking your battery to pay for it.

What's different

Most wearables buy HRV accuracy with a higher sampling rate or heavier upsampling — both of which cost battery life. Gen-2 gets there by extracting more from the same sampling budget instead of just sampling harder.

3. Calibrated for Every Skin Tone and Every Activity

Think of the ring's optical sensor like a camera. Getting a clean photo means balancing exposure — how much light you use, how sensitive the sensor is, and how long it "looks." Gen-2 tunes that same balance in real time: LED current (how much light the sensor emits), AFE gain (how sensitively the reflected signal is amplified), and integration time (how long each reading "exposes" for) all adjust automatically based on skin tone, blood flow characteristics, and whether you're resting or mid-workout.

Getting that balance right took extensive testing across a wide range of skin tones, body types, and activity levels — tuning the sensor to adapt to the person wearing it, rather than expecting every person to suit one fixed setting.

Did you know?

Optical heart rate sensors have historically been less consistent across different skin tones, because melanin changes how much light is absorbed versus reflected back to the sensor. Adaptive calibration — adjusting LED current, gain, and integration time for each person — is one of the more meaningful ways wearables can address that industry-wide challenge.

What's different

Gen-2 doesn't use one fixed sensor setting for everyone. LED current, AFE gain, and integration time all adapt in real time, tuned through extensive testing across skin tones and activity levels.

4. Fewer Interrupted Blood Pressure Readings

Gen-1 was strict about signal quality during a blood pressure reading — even a small artifact partway through would cause the whole measurement to be discarded, meaning you'd need to try again. Gen-2 takes a more adaptive approach: it adjusts to minor artifacts instead of discarding the reading outright, so measurements complete successfully far more often.

The result is a smoother, less repetitive experience getting a reading — fewer interruptions, fewer retries.

What's different

Gen-1 discarded a blood pressure reading at the first sign of a minor artifact. Gen-2 adapts to that artifact instead, so measurements complete successfully far more often.

5. More Stable Connections, By Design

A dropped Bluetooth connection is one of the more frustrating everyday moments with any wearable. Gen-2 addresses this from the hardware up: improved antenna placement strengthens the signal path between ring and phone, paired with reworked reconnection logic and a number of underlying stability fixes.

Together, they mean the ring reconnects faster and drops out less often.

What's different

Gen-2 addresses connection stability at the hardware level, not just in software — improved antenna placement plus reworked reconnection logic mean the ring finds its way back to your phone faster and drops out less often.

6. More Reliable Temperature Measurement

Temperature is a quietly foundational signal. Small shifts in your baseline skin temperature feed directly into how Ring One tracks sleep, cycle phase, and early signs of possible illness. A sensor that's only mostly accurate makes every one of those downstream metrics a little less trustworthy.

Gen-2's temperature sensor is accurate to within 0.1°C. But a highly accurate sensor is only half the story — it also needs an accurate signal to read in the first place. That's why Gen-2 introduces a thermally conductive material between your skin and the sensor, engineered to carry temperature changes through quickly rather than letting them lag or get dampened along the way.

Precision and conductivity together mean the sensor isn't just capable of fine-grained accuracy on paper — it's actually getting the clean, fast signal it needs to deliver that accuracy in practice. That translates directly into more reliable sleep tracking, cycle tracking, illness signals, and the other physiological parameters temperature feeds into.

Did you know?

A temperature sensor separated from your skin by even a small insulating gap reads a delayed, dampened version of your actual body temperature. That's why the material connecting skin to sensor matters as much as the sensor's own precision.

What's different

Gen-2 pairs a highly accurate temperature sensor with a thermally conductive path to your skin, so the accuracy on the spec sheet actually shows up in every reading — and in everything built on top of it, from sleep staging to cycle tracking to illness signals.

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New Features

Parts 1 through 3 covered what changed under the hood — hardware and algorithms. Part 4 is about what's genuinely new: capabilities Ring One didn't have before Gen-2.

1. Sleep Continuity Score: Why You're Tired, Even After 8 Hours

Most sleep tracking answers "how long did I sleep." It rarely answers the question people actually care about: why do I still feel tired after a full night in bed? Gen-2 introduces Sleep Continuity Score to go after that second question directly.

Continuity looks at how unbroken your sleep actually was — not just total time in bed, but how many times it was interrupted by brief awakenings you may not even remember the next morning. Frequent short interruptions can leave you just as tired as a night with too little sleep overall, even when the total hours look completely normal.

Each night is scored from 0 to 100 — Continuous (85+), Mostly continuous (70–84), Broken (50–69), or Highly broken (below 50) — and shown as a rolling 7-night average, so one rough night doesn't swing your score around.

The score is paired with a simple visual we call the night ribbon: a single band representing your night, physically broken wherever your sleep was interrupted. It's an immediate, at-a-glance picture of how continuous your night actually was, alongside two supporting numbers — micro-awakenings per hour, and restlessness, the percentage of the night spent moving.

Did you know?

Sleep researchers have long noted that fragmented sleep — frequent brief awakenings you don't consciously remember — can leave you feeling as tired as a shortened night, even when your total time in bed looks completely normal. Continuity Score is built specifically to surface that pattern instead of letting it hide behind a normal-looking total sleep duration.

What's different

Sleep tracking — including earlier versions of Ring One's — has mostly focused on total sleep time and sleep stages. Continuity Score adds a dimension most trackers skip: how unbroken that sleep actually was, which is often the real reason a full night in bed doesn't translate into feeling rested.

Continuity is a wellness metric — a way to understand your sleep quality, not a medical measurement.

Did you know?

Sleep apnea is one of the most common — and most under-diagnosed — sleep disorders in the world. Millions live with it for years without realizing it, and left untreated it's linked to chronic fatigue, poor concentration, and cardiovascular disease. The biggest problem isn't treatment — it's that most people never find out they should get tested.

Sleep Apnea: Better Decoded

To screen for Obstructive Sleep Apnea (OSA) from home without intrusive sleep lab studies or false alarms, Ring One uses a 2-Pronged Screening System:

• Prong 1: Clinical Risk Profiling (STOP-BANG): Uses the validated STOP-BANG framework (Snoring, Tiredness, Observed apnea, High Blood Pressure, BMI, Age, Neck circumference, Gender) to establish your baseline clinical risk profile.
• Prong 2: Multi-Night Corroboration (5-Night Strategy): Requires 5 valid nights of consistent biometric and motion alignment before flagging persistent OSA trends, effectively filtering out single-night anomalies like alcohol or acute fatigue.

When your continuity trend stays broken, the app can go one step further with an on-demand Apnea Check. In our preliminary validation for severe sleep apnea screening, it proved reliable at telling normal nights apart from concerning ones — so when it does flag a pattern, it's rarely a false alarm. The Apnea Check is a screening aid, not a diagnostic tool — if your results suggest a pattern, discuss them with a doctor.

2. RIO: An AI That Actually Knows Your Data

Most fitness apps show you data. RIO talks to you about it. It's a conversational AI built into the Ring One app with direct access to your own sleep, stress, activity, and recovery data — not a generic chatbot bolted on top, but one built specifically to read what your ring is already recording.

RIO isn't a one-way report, either. You can ask it anything, in plain language — why you feel off today, what's driving your stress this week, how to actually improve your sleep score — and it answers using your own data as the primary evidence, backed by general health patterns for people your age where your own history isn't enough on its own yet.

RIO's answers get sharper the longer you wear the ring, because it's building an actual personal baseline from your data rather than leaning on generic averages. In the first couple of weeks, it sticks to straightforward observations — what happened, and when. After about two weeks, it starts surfacing real patterns, the kind of thing you'd only notice by comparing weeks of data side by side. Give it a few months of consistent wear, and it moves into genuinely personal territory — connecting how your body specifically responds to travel, caffeine, back-to-back meetings, or training load, built from your own history rather than generic advice.

Did you know?

RIO waits for at least 14 days of your own data before it trusts a personal baseline over general population norms. Before that point, it's upfront that it's still learning you specifically, rather than guessing.

RIO can also just tell you the story of your day in plain language — no dashboard-reading required.

Your day, told by your ring — an example RIO daily summary. Click the image to view it full size.

3. Payments and Tesla Unlock, Coming with Gen-2

Two of the most requested capabilities for Ring One will be live with Gen-2 in the US: tap-to-pay and Tesla unlock. Paying for your coffee or unlocking your car will be as simple as a tap of your hand — no phone to dig out, no key fob to carry, no card to swipe.

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