Most people start with ONU using a device they already own — that's by design, and it works well. The ONU Bracelet exists for a different moment: after you've converted to ONU and seen what it does, for anyone who wants the most accurate, complete, and dedicated version of the experience. It's not a separate product line or an accessory bolted onto the app — it's the full-experience upgrade, available for an extra $99 on top of your ONU subscription: more compatibility with continuous, all-day tracking, more consistent analytics because nothing depends on a phone being nearby, and more accuracy on the metrics that matter most, like overnight HRV and sleep staging.
Not everyone tracking their health already owns a wearable — and not everyone who does wants a screen buzzing on their wrist all day. The ONU Bracelet was built for both of those people: a lightweight, screen-free tracker designed to run quietly in the background and feed directly into the ONU app.
Built to do one job
What the ONU Bracelet is built to do
The current model, ONU Series 3, is designed around one job: collecting continuous, passive health data without asking anything of you beyond wearing it.
Heart rate
Continuously, with notifications for readings outside your typical high or low range.
Sleep index
Feeds directly into your ONU Score's sleep component.
Blood oxygen
Ongoing background tracking throughout the day and night.
Stress index
Tracks stress load through the day based on heart data.
Cardio fitness signals
With notifications if your data suggests unusually low cardio fitness.
Blood pressure insights
Presented as algorithm-based estimates rather than direct medical measurements.
Every one of these signals feeds automatically into the ONU app the moment your bracelet syncs — no manual logging required.
Why screen-free is a deliberate design choice
A lot of wearables compete on how much they can show you in the moment. ONU Bracelet takes the opposite approach: no screen, no notifications buzzing throughout the day, just a nylon band and a flexible strap collecting data quietly until you check the app. The idea is that a wearable's job is to collect good data, not compete for your attention — the interpretation and action planning happen in the ONU app, where there's room to actually explain what a reading means instead of flashing a number on your wrist.
Battery
Battery life built for actually wearing it
Up to 22 days on normal use, roughly 30 in battery-saving mode, and a full charge in about 45 minutes — because sleep data only matters if it's actually collected every night.
Who it's for
Who the Bracelet is for
Already using another device
Anyone who's already using ONU with another device and wants to upgrade to the full experience.
Starting from zero
Anyone who wants continuous tracking without an existing wearable.
Tired of charging
Anyone frustrated by short battery life on other devices.
Wants screen-free
Anyone who specifically wants the "checking in on my health" moment to happen intentionally in an app, not passively on a wrist display all day.
It's the same recommendation whether you're an athlete wanting the most accurate recovery data or someone with a standard 9-to-5 schedule wanting the most complete picture with the least effort — the Bracelet's whole job is removing the accuracy gap that comes from relying on a phone or a secondhand device.
Details
Everything else worth knowing
Durability, what's in the box, comfort, philosophy — pick a topic instead of scrolling through all of it.
FAQ
Frequently asked questions
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Tracked continuously, day and night
Notifications for readings outside your typical high or low range — no need to open the app to know something's off.
Feeds directly into your ONU Score
Every night the Bracelet tracks becomes part of the sleep component of your daily score — no manual logging required.
Ongoing background tracking
Measured throughout the day and night without you having to trigger a manual reading.
Your stress load, tracked through the day
Based on heart data captured continuously by the Bracelet — the same signal that feeds your ONU Score's stress component.