±0.01°
Temp accuracy
8 days
Battery
4 g
Titanium
100 m
Water safe
The Halo Ring
THE RING THAT
READS YOUR CYCLE.
Temperature, sleep, recovery, stress, readiness, movement — plus a blood-sugar trend no other ring reads. Gathered while you sleep, translated by your care team before you wake.
$250
one time · no subscription
60-day guarantee
Free shipping
Tracking free forever
Choose your color
Choose your size
Sizing guide
Pick a color and size to continue
Included free
The Conceivable app, all six signals, your full history — no paywall. Kai's AI advising is a separate, optional membership you can try free.
What it reads
SIX SIGNALS, READ FOR
WHAT THEY SAY ABOUT YOU.
Every signal is interpreted for your hormones, not your training load — and each one is a feedback loop that lets Kai check her own work and revise your plan.
Also monitored, 24/7
Continuous heart rate · oxygen saturation · VO₂ max & fitness age · blood-pressure trend · all-day activity. Read from the palm side of your finger, where the pulse is strongest.
One ring, six chapters
CALIBRATED FOR EVERY
PHASE OF YOU.
The only wearable tuned to all phases of women's health. Tap a stage.
Why the Halo
NOT JUST ANOTHER RING.
What women say
WORN EVERY NIGHT.
TRUSTED EVERY MONTH.
Real buyer photos
Real hands, real rings — unedited photos.
Good to know
QUESTIONS, ANSWERED.
General wellness product
The Halo Ring and the Conceivable app are general wellness products intended to support a healthy lifestyle. They are not intended to diagnose, cure, mitigate, prevent or treat any disease or condition, are not a substitute for an FDA-cleared device, and do not replace care from your clinician. All signals are non-invasive estimates and trends — not clinical measurements, and not diagnostic thresholds. If something in your data looks unusual, we will encourage you to talk with your healthcare provider.
The Halo Ring · $250 · 60-day guarantee · Tracking free, forever.