Your watch tells the time.Stealthy tells you the rest.
A screenless health sensor that hides in the clasp of the watch you already own. The Stealthy Band, in the box, covers the hours the watch comes off.
An illustration, not measured data.
$199 $249 once. No subscription.
$50 off until November 30 with codeApplied for you at checkout.
Ships December 2026. Full refund any time before it ships.
The Stealthy app syncs with Apple Health and Health Connect
Stick it. Pair it. Forget it.
Watch + Band + App: one shared stream
The problem
Every tracker asked you to take something off.
The watch you love. The ring you earned. Your identity.
Stealthy is the first one that asks for nothing.
It disappears into the clasp of the watch you already own,
and starts listening.
The Stealthy Clasp
Stick it. Pair it. Forget it.
Stick it
One die-cut mount on the flat inner face of your clasp. No tools, no change to the watch. Six spare mounts in the box for moving it between watches.
Pair it
Open the app, tap the Clasp it finds, done. It is told who wears it and starts a record. Pair the Band the same way; it takes over the moment the watch comes off.
Forget it
Eight days on a charge. No screen, no buzz, no glance at the wrist in a meeting. The app tells you what matters, in the morning and in the evening.
After validating over 100 adhesive formulations, the mounting system is built for a 0.25mm flush bond that holds through water, sweat, and daily wear:
- Engineered for versatility, Stealthy mounts securely to most steel bracelets, leather bands, and rubber straps. It is designed to be easily detachable and transferable between timepieces, arriving with six proprietary adhesive strips so you can seamlessly transition it across your curated watch collection.
- Zero Residue: Guarantees 100% clean removability from luxury watch metals without marring.
- Universal Adaptability: Includes 6 spare die-cut mounts (three at 0.25mm, three at 1.1mm) allowing you to effortlessly move your tracker between flat surfaces and complex curved clasps.
- Water-resistant & secure: Built for all-day wear, sweat and rain, rated 3ATM.
- Frictionless Application: Effortless to apply and easy to remove when it is time for a change.
The Stealthy Band
Your watch comes off at night. Your record doesn't.
Nobody sleeps in a steel bracelet, and nobody runs in a dress watch. Yet the night is where every morning number comes from, including the sleep score, your HRV baseline, body energy and the focus potential for the day. A sensor that lives in a clasp on the nightstand would leave all of that blank.
So the box holds two. The Clasp wears the watch by day. The Band, a soft loop you forget you have on, wears the night, the run and the gym. Same measurements, same account, one unbroken record.
One record, never two
Both devices send what they saw. The app gives each moment to one of them, so a run is counted once and a night comes whole from one device.
The Band leads when both are near
Clasp on the dresser, Band on the wrist, and the Band is the source. Nothing to choose, nothing to switch.
A worn Clasp is never interrupted
Walk past the Band on the nightstand with the watch on and nothing changes. The Clasp keeps the day until it is taken off.
Proven metrics
World-class tracking.
Zero wrist presence.
Precise health and activity intelligence, truly invisibly. Continuous monitoring, ultimate comfort. The feed below is an illustration, not measured data.
Heart Rate
live61bpm
Continuous beats-per-minute, resting and active, with zero wrist glow.
HRV
live55ms
Heart-rate variability, read against your own baseline for stress and recovery.
Blood Oxygen
live98%
Night-time and on-demand oxygen-saturation wellness trends.
Sleep Score
live83/100
Light, deep and REM staging with a nightly recharge score on wake.
Stress Load
live22idx
Physiological load from heart rate and HRV against your own baseline, hour by hour.
Daily Activity
live7,400steps
Steps, distance, active minutes and calorie estimates for the day.
Biological age
A risk-equivalent age from your resting heart rate, steps and sleep, in whole years and drawn from published research. A wellness estimate, not a medical measurement.
The app - iOS & Android
All the metrics. None of the noise.
Built for the professional who takes health seriously, demands mental clarity, and refuses to trade a beloved timepiece for another screen.
Activity
Focus index
Deep work session
Energy today
Stress insights
Stress on your calendar
Calendar integrations
Vitals
Morning signal
Workout start
In progressLive workout
Calendar
Find out which meetings cost you.
Connect Google Calendar or Microsoft 365 and your stress trace is laid over your real day. Every meeting shows the stress recorded during it, and every gap shows whether you settled before the next one.
- In meetings
- 3h 30m
- Gaps recovered
- 2 of 3
- Longest elevated
- 40m
Your calendar never leaves your phone.
Works with
- Recurring meetings build a track record, such as elevated in 3 of the last 4 weeks.
- Up to five calendars, each in its own colour: work, personal, shared. iCloud and others connect by private link.
- One switch masks every event title, so blocks read only as busy time.
- Read on the phone. Nothing from your calendar is sent to a server, not even to write your briefing.
On the TV
Cast your vitals to a Chromecast or Apple TV to see your stats live while you work out.
Roll out the mat, step onto the treadmill or start a set, and send the workout to the TV. Heart rate, zone, time and the breathing guide, live and large, so you never stop to look at a phone.
- Vitals between sessions, the workout board during one, the recap after. Chromecast and Google TV from either phone; a mirrored screen works too.
- Only the board is shown. The code on the TV unlocks it, so it is yours alone.
- When the workout ends, the recap stays on the screen until you stop it.
- Heart rate
- 75
- Resting heart rate
- 58
- HRV
- 48
- Sleep
- 7h 12m
Compare
How Stealthy compares.
Next to Whoop, Oura and the Apple Watch.
Competitor details come from each maker's public pages on 3 October 2026 and change over time. Stealthy's figures are those of the validated sample.
Technical specifications
The full spec sheet.
No vague promises. These are the figures the sample was validated against.
Show the full specificationsHide the specifications
- Dimensions
- 30mm x 12mm x 4.2mm
- Weight
- 10 to 20 g
- Battery life
- 8 days
- Water resistance
- 3ATM
- Charging
- Magnetic charging cable
- Materials
- Resin and stainless steel (Stealthy Clasp); zinc alloy and resin (Stealthy Band)
- Offline storage
- Up to 2 days of data without a phone
- Sensors
- PPG, accelerometer
- Connectivity
- Bluetooth Low Energy
Specifications apply to both the Stealthy Clasp and the Stealthy Band.
Charging
Seamless charging.
Both the Stealthy Clasp and the Stealthy Band can be charged with the one charging cable included in the box.
Stealthy Clasp
1.5 hours
Empty to full on the shared charging cable.
Stealthy Band
2 hours
Empty to full on the same charging cable.
Certifications
Being certified for both devices.
The Stealthy Clasp and the Stealthy Band are being validated against the same compliance standards, in every market we ship to.
FCC
United States radio-frequency compliance
CE
European conformity (health, safety, EMC)
RoHS
Restriction of hazardous substances in electronics
Australia RCM
Regulatory Compliance Mark for Australia
Australia CSR
Cyber Security Requirement for connected devices
Certifications are in progress and targeted for both devices ahead of the production run.
Transparent pre-order
Pre-order now for delivery in December 2026.
Your payment is the full price of a complete unit: the Stealthy Clasp, the Stealthy Band and their charging cable, shipping in December 2026. One charge, no subscription, and a full refund any time before it ships.
What's in the box
- × 1
Stealthy Clasp
Attaches to the clasp of your watch. The adhesive mount is already fitted.
- × 1
Stealthy Band
For the run, the gym and sleep, when the watch comes off.
- × 3
Standard spare mounts
0.25 mm adhesive pads, 25 × 10 mm, to move the Clasp between watches.
- × 3
Thick spare mounts
1.1 mm adhesive pads for uneven clasps.
Surface prep wipes
Degrease the metal clasp before fitting, if needed.
- × 1
Charging cable and install card
One magnetic cable charges both the Clasp and the Band.
Whether you are wearing the Stealthy Clasp or the Stealthy Band, the app keeps a single unbroken record of your day.