Engineered to be worn, built to be forgotten
Aerospace-grade titanium, medical-grade sensors and a week of battery — in 2.9 grams you'll stop noticing by lunch. This is the hardware behind your eight skin scores.
Four signals, read all day and night
i do samples continuously and syncs quietly to the app — no tapping, no thinking about it.
Skin temperature
Accurate to ±0.005°C. Overnight temperature shifts help map your cycle phase and flag when your skin barrier is under strain.
Optical heart rate
Resting and continuous heart rate reveal recovery, stress load and sleep quality — all of which show up on your skin.
Blood oxygen (SpO₂)
A window into overnight breathing and circulation, part of the picture behind your Glow and Barrier scores.
Heart-rate variability
HRV tracks how well you're recovering. Low HRV days are when your skin most needs a gentle routine.
A week between charges.
Fine in the shower.
Most smart rings ask for a charge every couple of days. i do runs 4–7 days on a charge and tops up in about an hour on its magnetic dock — so it’s on your finger when the readings matter: overnight.
Three finishes. One quiet confidence.
Gold
14K gold-tone finish
PhotographedSilver
Brushed titanium
Shown as swatchSpace Black
Matte space black
Shown as swatchFind your fit
| US size | Circumference | Inner Ø | Outer Ø |
|---|---|---|---|
| 6 | 51.8 mm | 16.5 mm | 22.4 mm |
| 7 | 54.7 mm | 17.4 mm | 23.3 mm |
| 8 | 57.2 mm | 18.2 mm | 24.1 mm |
| 9 | 59.7 mm | 19 mm | 24.9 mm |
| 10 | 62.5 mm | 19.9 mm | 25.8 mm |
| 11 | 65 mm | 20.7 mm | 26.6 mm |
| 12 | 67.5 mm | 21.5 mm | 27.4 mm |
| 13 | 70.1 mm | 22.3 mm | 28.2 mm |
Ready when you are.
Titanium, a week of battery, and eight skin scores waiting for you.