Measured to the
millimetre.
Four millimetres of custom silicon. Six sensors. Seven days of battery. Engineered for five years before a single one ever shipped.
4 mm²
sensor footprint
7 d
battery
100 m
water depth
4.2 g
total weight
Honest signals from the
tip of your finger.
Optical heart-rate
5 LEDs · 250 Hz samplingContinuous BPM and HRV at rest, during workouts, and through every sleep stage.
SpO₂
Pulse-oximetry, night-only modeNightly blood-oxygen variance to surface sleep-disordered breathing patterns early.
Skin temperature
±0.1 °C precisionSub-degree resolution for cycle tracking, illness onset and recovery readiness signals.
6-axis IMU
Accelerometer + gyroscopeDetects activity, sleep positions, and steps without ever needing a phone in your pocket.
Seven days.
Ninety minutes.
A 35 mAh solid-state cell pushes seven full days between charges — and refills completely in 90 minutes on the included magnetic dock. Charge it while you shower. Forget it for a week.
7 d
per charge
90 m
full charge
35 mAh
solid-state
What touches your skin
matters more than the chip.
Grade 5 titanium
Hypoallergenic, 4× harder than steel, ages without scratching.
Sapphire crystal
The sensor window is 9H hardness — second only to diamond.
DLC coating
Diamond-like carbon inner band, biocompatible and salt-resistant.
Built to be forgotten.
100 m water-resistance. Drop-tested to 2.5 m on tile. Salt-water cycled for 30 days with zero corrosion. Sapphire sensor window outlives every scratch your hands invent.
FDA Class II
CE marked
FCC ID
IP68
IEC 62133
EN ISO 10993
Enough words.
Try one on.
$349. Free shipping. 30-day risk-free trial. Two-year warranty.