A smart ring is not a normal ring. The sensors read through the base of the finger, so the fit decides whether you get usable data at all.

How to measure correctly

• 1 Measure the exact finger on the exact hand you will wear it on. A US 8 on the left ring finger is not a US 8 on the right index finger.

• 2 Measure at the base of the finger , not the middle. The band sits low, above the knuckle.

• 3 Measure at the end of the day . Fingers swell; a fit that works in the morning can be tight by evening.

• 4 It should feel secure, not painful . If it spins freely it is too loose. If it leaves a deep mark after an hour, it is too tight.

• 5 When in doubt, wear the sizer for 24 hours before you decide — including a night's sleep.

The sizer kit contains every size in the range and its cost is credited toward your ring order. It is the only reliable way to get this right.

Order a sizer kit

Conversion table

Size — Inner diameter — Circumference — Weight

US 6 — 16.5 mm — 44.2 mm — 3.6 g

US 7 — 17.3 mm — 45.0 mm — 3.6 g

US 8 — 18.1 mm — 45.8 mm — 3.6 g

US 9 — 18.9 mm — 46.6 mm — 3.6 g

US 10 — 19.8 mm — 47.5 mm — 3.6 g

US 11 — 20.6 mm — 48.3 mm — 3.6 g

US 12 — 21.4 mm — 49.1 mm — 3.6 g

US 13 — 22.2 mm — 49.9 mm — 3.6 g

All OSAWALLA rings ship in US sizes 6–13. Sizer kits cover US 6–14 so you can confirm a neighbouring size if you are between two.

• Free US shipping On orders over $50

• 30-day returns Unused and resalable

• 12-month warranty Against manufacturing defects

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