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The tracker you forget you're wearing.
Aro One weighs less than a coin, has no screen to distract you, and runs for days on a single charge. Slip it on and it quietly maps how you sleep, how hard you push, and how well you bounce back.
Free shippingEvery order, no minimum
30-day returnsWrong size? We swap it
No subscriptionThe app is free, forever
Real supportA human replies in 1 business day
Why a ring instead of a watch
Aro One
Typical smartwatch
Comfortable to sleep in
Yes
Most people take it off
Battery between charges
Days
Usually overnight
Screen and notifications
None at all
Constant
Weight on the body
~3–4 g
30–60 g
Monthly fee for data
$0
Often required
Works with a dress shirt cuff
Invisible
Bulky
Price
$49.95
$200–$400
What Aro One tracks
Sleep. Time asleep, restlessness, and how your nights trend across weeks.
Heart rate trends. Continuous readings through the day and overnight.
Activity & steps. Movement, active minutes and calorie estimates.
Readiness. A daily score blending sleep and activity — push today, or take it easy.
Wrap a strip of paper around the base of your finger, mark where it overlaps, compare to a standard ring size chart.
Measure at end of day when fingers are largest.
Most people choose index or middle finger. Between two sizes? Go up.
Sized wrong? Message us within 30 days — we'll swap it.
Ordering
Free shipping on every order
Typically arrives in 10–16 business days
30-day returns and exchanges
Tracking sent as soon as your ring leaves the warehouse
A note on health data. Aro One Smart Ring is a general wellness and fitness product. It is not a medical device, has not been evaluated by the FDA, and is not intended to diagnose, treat, cure or prevent any disease or condition. Readings are estimates meant to help you spot patterns over time, not clinical measurements — don't use them to make medical decisions. If you have concerns about your heart, your sleep or your health generally, talk to a qualified healthcare professional.