Colmi R09, the $20 smart ring
The sleep data matched my Apple Watch. Colmi’s sizing guide didn’t.WearablesTested 1 weekOct 12, 2026
Wearables
I wear a watch and a smart ring every day, through workdays, nights and travel. I pay attention to what I use daily and what I never touch, battery in real days, sleep tracking against what I know about my own nights, and whether the software is still being updated. Scores reflect months of wear, and a model that lost support loses points for it.
Apple Watch Ultra (1st gen) after watchOS 27
Apple dropped it from watchOS 27. That changes who should buy one used.WearablesTested 10 monthsSep 29, 2026
Wearable guides
Colmi R09 sizing: how to pick your size before you order
Measure the exact finger you'll wear the Colmi R09 on, then match its circumference to Colmi's chart. Colmi's guide sent me a size 11 that didn't fit my index finger, and the store only takes back unworn rings.WearablesNov 6, 2026Colmi R09 vs Oura Ring 5: start with the $20 ring
Buy the Colmi R09 first. It costs $20 to $60 with no subscription, and on the nights it fit, it matched my Apple Watch Ultra. Pay $399 plus $69.99 a year for Oura only for the app.WearablesNov 6, 2026Colmi R09 vs R02: I wear the R09, and it's the cheap ring to buy
Buy the Colmi R09. It costs $4 more than the R02 at Colmi's store, and it's the one of the two with confirmed skin temperature. I wear the R09; the R02 side is from Colmi's specs and Gadgetbridge.WearablesOct 27, 2026How to make an Apple Watch battery last a workday and a night of sleep tracking
Charge it on a schedule, two short top-ups at fixed times. Then turn off Always On, stop mirroring every iPhone alert, use Low Power Mode on flights and check battery health.WearablesOct 23, 2026Which Apple Watch to buy in 2026: SE 3, Series 12 or Ultra 4?
Buy the $449 Series 12 in 46mm aluminum: thin enough to sleep in, with Apple's new heart sensor. The $249 SE 3 covers Apple Pay. Ultra only for two-day battery.WearablesNov 6, 2026Best sleep tracker in 2026: ring, band or watch?
The best budget sleep tracker is the $20 Colmi R09 ring. Upgrade to the $349 RingConn Gen 3 if it sticks. Oura, Whoop, Fitbit Air and Apple Watch compared.WearablesOct 31, 2026