Ring 3 Pro / Slim
The Circular Ring 3 Pro / Slim is a smart ring, announced for 2027. Two-size titanium follow-up bringing NFC payments and vibration alerts to both models, with ECG and blood-pressure trends reserved for the 12-day Pro.
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Generations
| Generation | Year | Status | Price | Weight |
|---|---|---|---|---|
| Ring 3 Pro / Slim | 2027 | Announced | TBD | Not disclosed |
| Ring 2 | 2026 | Shipping | $349 | 4 g |
Specifications by generation
Ring 3 Pro / Slim
2027AnnouncedTwo-size titanium follow-up bringing NFC payments and vibration alerts to both models, with ECG and blood-pressure trends reserved for the 12-day Pro.
- Category
- Ring
- Worn
- Finger
- Release
- 2027
- Price
- TBD
- Weight
- Not disclosed
- Sensors & hardware
- Biometric
- Motion
- Input
- Connectivity
Developer access
- SDK / APINot verified
Developer support for this generation is unverified. The company/platform program must not be assumed to support this hardware.
Not yet verified: documentation, app distribution, vendor-server requirements and hardware and software openness.
Openness, servers & distribution
- hardware
Schematics, mechanical designs and firmware publication were not verified.
- firmware
Source availability and licensing were not established in this review.
- companion apps
Source availability and licensing were not established in this review.
- SDK
Source availability and licensing were not established in this review.
- backend services
Source availability and licensing were not established in this review.
- Vendor servers
Vendor-server requirements were not established for this device.
- App distribution
Third-party app distribution was not verified.
A companion app or integration is not evidence of a third-party app store.
Ring 2
2026ShippingTitanium ring built around an on-finger single-lead ECG with AFib detection and PPG-based blood-pressure estimation.
- Category
- Ring
- Worn
- Finger
- Release
- 2026
- Price
- $349
- Weight
- 4 g
- Sensors & hardware
- Biometric
- Motion
Developer access
- Circular API / SDK restricted/private preview
- Selected-project API/SDK integration
- Multi-account health-data dashboard and CSV exports
API/export access is limited to selected projects and requires contacting Circular. Business page advertises 25-unit minimum orders; full API reference, supported platforms and Ring 3 compatibility remain unverified.
- Documentation
- public
- Vendor servers
- required
For the documented account/cohort dashboard route: wearer accounts and consent are required; Circular describes backend registration, ring-data uploads and health processing. This does not establish that every ring function requires a network connection.
Not yet verified: app distribution and hardware and software openness.
Openness, servers & distribution
- hardware
Schematics, mechanical designs and firmware publication were not verified.
- firmware
Source availability and licensing were not established in this review.
- companion apps
Source availability and licensing were not established in this review.
- SDK
Source availability and licensing were not established in this review.
- backend services
Source availability and licensing were not established in this review.
- Direct / local access
CSV export through the vendor dashboard is documented; a vendor-independent raw/BLE/offline API was not verified.
- Own backend
Selected projects can integrate data into their own products, but replacement of the Circular backend is not documented.
- Third-party cloud
Amazon Web Services, Paris region, for documented storage and disaster recovery
- App distribution
Third-party app distribution was not verified.
A companion app or integration is not evidence of a third-party app store.
- References
Company & funding
Circular
Rewards crowdfunding confirmed; equity/debt financing and current corporate status remain unknown.
- Disclosed funding
- USD 4.08M
Ring 2 Kickstarter rewards pledges only, March 5–April 14, 2025; excludes equity, debt, other campaigns and retail sales. Campaign reports 13,695 backers and USD 4,078,500 pledged. This is gross campaign pledges, not net proceeds or lifetime corporate financing.
- Disclosed rounds
- 1
Among makers in the index
Rounds
2025-04-14
Ring 2 Kickstarter campaignUSD 4.08M
Rewards crowdfunding
Not equity/debt, net proceeds or corporate valuation.
Valuation not disclosed
Valuation was not disclosed in the reviewed evidence.
Company
Current product/privacy pages identify the Circular brand/group but do not establish the precise operating legal entity, parent or any continuity with historic entities.
Not yet verified: valuation and named investors.
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Independent index — figures are approximate and editorial, not official spec sheets. Methodology. Last reviewed 2026-10-31.