Multi-biometric
HR, HRV, SpO2, skin temperature and sleep — captured continuously at research-grade fidelity, not just step counts.
Sage + Stone hardware · Pre-launch
HSA/FSA: may be eligible with a Letter of Medical Necessity
Sage + Stone Band
The multi-biometric band that captures every signal at the source.
The #1 reason to choose the Band
Worn on the upper arm — more accurate than a wrist wearable.
At the wrist, optical heart-rate and HRV readings are degraded by wrist motion, loose fit, and the tendons that crowd the sensor against the skin. The upper arm sits over a steadier bed of muscle and blood flow — the same reason chest straps and arm bands beat watches for heart rate and HRV. Sage + Stone reads from that cleaner window, so the data reaching your unified read is the data worth trusting.
$179
$99
Founding price one-time ships 2026*
Finish Sage
Founding pre-order · charged today · fully refundable until it ships (2026)
Private by design
Feeds your unified read
2-year warranty
Big signals, small band
Built to read the whole you
Worn on the upper arm — the cleanest optical window on the body — so the data that reaches Sage + Stone is the data worth trusting.
All-day comfort
A soft woven band that disappears on your arm. Up to 7-day battery and water-resistant to 50 m — wear it through workouts, showers and sleep.
Feeds your unified read
Every signal flows straight into one Sage + Stone timeline — reconciled with your other devices and read each morning by your AI coach.
What it powers
Your body talks. Sage + Stone translates.
One band, read across every system — so the same wrist of data becomes recovery, sleep, heart, stress and metabolic insight at once.
Recovery
A daily readiness read from overnight HRV, resting HR and temperature trend.
Sleep & rest
Staged sleep, latency and disruptions — reconciled with the rest of your stack.
Heart health
Continuous HR and HRV with resting-rate and rhythm trends over time.
Stress
Day-long load from HRV and skin temperature — see when to push and when to ease.
Metabolic
CGM-ready: pair a glucose sensor and the band aligns it with sleep and activity.
Women’s health
Temperature-based cycle and phase tracking, folded into your daily read.
Good to know
Questions, answered
How accurate is the Sage + Stone Band?
The upper arm is one of the most stable optical sites on the body, with far less motion noise than the wrist. Paired with a multi-LED optical array and an onboard accelerometer for motion rejection, the Band targets research-grade HR and HRV. It’s built for everyday wellness insight, not medical diagnosis.
Is it water-resistant?
Yes — the sensor module is water-resistant to 50 m, so you can swim, shower and sweat without taking it off. The woven band is quick-drying and machine-washable once the module is removed.
How long does the battery last, and how do I charge it?
Up to 7 days on a charge with continuous sensing. The module pops out and charges over USB-C — a full charge takes about 60 minutes, and a quick 10-minute top-up covers a full day and night of wear.
How do I get the right size?
Three sizes — Small, Medium and Large — cover upper-arm circumferences from 22 to 38 cm, and each band adjusts within its range. Measure your upper arm or use the printable sizing guide. If it’s not perfect, free returns make swapping easy.
Do I need the Sage + Stone app or a membership?
The Band pairs with the free Sage + Stone app (iOS and Android) for your daily read — no subscription required to see your own data. A Sage + Stone membership unlocks the AI coach, early-warning alerts and cross-device reconciliation, but the Band is yours to use either way.
The details
What’s in the box & under the hood
Technical specifications
| Sensors | Optical HR/HRV array with multi-LED SpO2, a dedicated skin-temperature sensor, and a 3-axis accelerometer for motion rejection. |
|---|---|
| Metrics | Heart rate, heart-rate variability, blood-oxygen (SpO2), skin temperature, sleep stages, respiration trend. |
| Materials | Anodized-aluminum sensor module with a soft, breathable woven band. Hypoallergenic, machine-washable strap. |
| Battery | Up to 7 days per charge · USB-C magnetic charging · ~60-min full charge. |
| Connectivity | Bluetooth Low Energy · pairs with the Sage + Stone app for iOS and Android. |
| Water resistance | 50 m (5 ATM) — swim, shower and sweat-proof. |
| Wear & fit | Upper-arm wear · sizes S / M / L · fits 22–38 cm circumference. |
| In the ecosystem | CGM-ready · feeds the Sage + Stone unified read, AI coach and early-warning alerts. |
Pre-launch · ships 2026
Be first to wear the source of truth
Pre-order the Sage + Stone Band at the founding price. Your card is charged today and it’s fully refundable any time before it ships in 2026 — and your spot in the first production run is locked in.
$99 founding (reg. $179) · HSA/FSA: may be eligible with a Letter of Medical Necessity · fully refundable · free returns