By: Anushka Verma | Updated: October 25, 2025
In the world of wearable technology, innovation never sleeps. From smartwatches that analyze our sleep cycles to fitness bands that measure every step, health-focused tech has rapidly evolved. Yet, the next big leap in personal health monitoring isn’t happening on your wrist — it’s happening on your finger. Enter the Circular Ring 2, a $239 smart ring that might soon outshine even the most advanced smartwatches by introducing blood pressure and glucose level trend tracking.
Designed by the French startup Circular, the Ring 2 has already made waves across the tech industry. It’s compact, sleek, subscription-free, and powered by some of the most advanced biosensing technology in the market. And what’s most exciting — it promises features that giants like Samsung and Oura are still developing for their own upcoming rings.
Circular’s vision is clear: to make health data more personal, accessible, and private — without locking users behind paywalls. Let’s explore what makes this ring one of the most ambitious wearables of 2025.
The Evolution of Smart Rings
The idea of tracking health metrics through a small ring seemed futuristic only a few years ago. Early versions like the first Oura Ring introduced the world to the concept of sleep and heart rate tracking through finger-based sensors. But back then, accuracy and sensor reliability were still growing pains.
With the Circular Ring 2, the company has taken several technological leaps — including improved accuracy, expanded health metrics, and the potential for blood pressure and glucose trend monitoring — something even Apple and Samsung have yet to perfect.
The result is a device that combines aesthetic elegance with medical-grade intelligence, all in a form so light and stylish that most users forget they’re even wearing it.
Key Specifications and Technical Overview
The following table provides a complete breakdown of the Circular Ring 2’s specifications and features:
| Feature | Details |
|---|---|
| Product Name | Circular Ring 2 |
| Manufacturer | Circular (France) |
| Price | $239 (Kickstarter early backers) |
| Battery Life | Up to 5 days per charge |
| Charging Time | 60–90 minutes |
| Sensors | PPG, SpO₂, heart rate, skin temperature, accelerometer |
| Connectivity | Bluetooth 5.3 |
| Compatibility | Android and iOS |
| Subscription Model | None (All features included) |
| Water Resistance | Up to 50 meters |
| Body Material | Titanium with hypoallergenic coating |
| Available Colors | Black, Silver, Gold, Rose Gold |
| App Integration | Circular App with AI-based insights |
| Weight | 3–4 grams (varies by size) |
Circular’s approach to hardware design focuses on three key elements — comfort, durability, and data precision. The titanium shell ensures strength without bulk, while the inner surface hosts multiple micro-sensors that continuously read bio-signals without discomfort.
Design and Comfort
Visually, the Circular Ring 2 strikes the perfect balance between elegance and technology. The outer shell is smooth, available in four subtle metallic shades, and can be customized for different styles. The inner layer — where the sensors are embedded — is curved to fit naturally around the finger.
The design allows 24/7 wearability, including during workouts, showers, and even sleep. The magnetic charging dock is sleek and travel-friendly, taking under 90 minutes to recharge the battery completely.
Its featherlight weight and ergonomic design make it suitable for long-term wear — something that early adopters of bulkier smart rings often struggled with.
Circular also offers an optional sizing kit to ensure users find the perfect fit for maximum accuracy.
Advanced Health Tracking Features
While the Circular Ring 2 can monitor all the basics — heart rate, sleep stages, activity levels, and body temperature — its real innovation lies in the features that most smartwatches still don’t have.
The company’s research and development team has focused heavily on non-invasive biosensing, with two headline features expected to redefine wearable health: blood pressure monitoring and blood glucose trend tracking.
How Blood Pressure Monitoring Works
The Circular Ring 2 doesn’t use traditional cuffs or wrist-based photoplethysmography to measure blood pressure. Instead, it relies on Pulse Transit Time (PTT) — the amount of time it takes for a pulse wave to travel through the arteries.
By analyzing PPG (photoplethysmography) signals and motion sensor data, the ring estimates the pressure level of your blood flow. This process takes 30 seconds to 2 minutes, depending on your circulation and activity.
Circular’s AI then translates these readings into systolic and diastolic trends, providing insights into how stress, exercise, and recovery influence your blood pressure throughout the day.
Although this feature is still awaiting regulatory validation, Circular has confirmed that it will be released through an OTA (Over-the-Air) software update by late 2025. Once available, it could set a new benchmark for non-invasive cardiovascular monitoring in compact devices.
Glucose Trend Tracking — The Next Breakthrough
Circular isn’t stopping at blood pressure. The next frontier for the Ring 2 is glucose trend analysis, expected to arrive in late 2026.
This feature will not offer medical-grade precision but will provide valuable insights into glucose variability — how food, exercise, and sleep affect your blood sugar trends.
The technology behind it involves PPG sensors combined with machine learning models that interpret how light interacts with blood under the skin. These micro-fluctuations in reflected light can indirectly indicate glucose changes.
While it won’t replace medical-grade glucometers or continuous glucose monitors (CGMs), the Circular Ring 2 aims to provide an early-warning system and daily pattern tracking for general wellness.
Data Accuracy and Limitations
Non-invasive biosensing technology has always walked a fine line between innovation and accuracy. Circular acknowledges this challenge openly.
Blood pressure readings may vary depending on finger size, temperature, or movement, and glucose tracking is still in its experimental phase.
However, Circular’s engineers emphasize trend-based monitoring rather than single-point readings. This approach aligns with wellness-focused applications, helping users understand long-term patterns instead of providing medical-grade diagnoses.
Early tests indicate that the blood pressure feature could achieve a ±5 mmHg accuracy range, putting it in line with many wearable health monitors already approved for general wellness use.
Complete Health Ecosystem
Circular’s companion app integrates seamlessly with both Android and iOS, offering a unified dashboard that combines sleep, activity, and recovery insights.
It provides daily readiness scores, stress tracking, and sleep quality metrics — much like Fitbit or Oura — but without locking features behind paywalls.
Some of its standout features include:
| Feature | Function |
|---|---|
| Sleep Analysis | Tracks sleep stages, deep vs. REM cycles, and rest quality |
| Activity Monitoring | Steps, calories burned, and movement patterns |
| Heart Rate Variability (HRV) | Measures recovery and stress levels |
| SpO₂ Monitoring | Tracks blood oxygen levels |
| Skin Temperature Tracking | Detects subtle body temperature shifts |
| AI Insights | Personalized health recommendations based on habits |
The Circular app uses on-device AI processing to enhance privacy while still learning from user data. This ensures your health data remains secure and locally stored whenever possible.
Privacy and Subscription-Free Philosophy
In an era when most wearable companies lock their best insights behind monthly plans, Circular has taken a different path. The Ring 2 requires no subscription fees — every feature, including future updates, is free for all users.
This model not only enhances affordability but also builds trust. Users retain complete ownership of their data, which can be exported or deleted at any time.
Circular’s privacy-first approach aligns with European GDPR standards, emphasizing transparency and user control.
Kickstarter Success Story
The Circular Ring 2’s journey began as a Kickstarter campaign that rapidly gained momentum. Within weeks, it crossed the $1 million mark, signaling massive public interest.
Backers were drawn not just to the ring’s futuristic capabilities but also to its transparent promises. Unlike many crowdfunding campaigns, Circular already had a working prototype demonstrated at CES 2025, proving that this wasn’t a far-fetched concept but a nearly finished product.
Following this success, the company officially opened global pre-orders, offering early-bird discounts and free accessories for backers. The first batch of shipments is expected to begin later this year.
Circular Ring 2 vs Galaxy Ring vs Oura Ring
As competition intensifies, here’s how the Circular Ring 2 stacks up against its most talked-about rivals:
| Feature | Circular Ring 2 | Samsung Galaxy Ring | Oura Ring Gen 3 |
|---|---|---|---|
| Price | $239 | Expected $350–$400 | $299 |
| Blood Pressure Tracking | Coming via OTA update | Under development | No |
| Glucose Trend Tracking | Coming in 2026 | Not announced | No |
| Subscription | None | Likely (Samsung Health+) | Yes ($6.99/month) |
| Battery Life | 5 days | 6–7 days (expected) | 5–6 days |
| Water Resistance | 50m | 50m | 100m |
| App Ecosystem | Circular App | Samsung Health | Oura App |
| Sleep Tracking | Yes | Yes | Yes |
| AI Insights | Yes (local) | Yes (cloud-based) | Yes |
Circular’s biggest competitive edge is its no-subscription model and focus on non-invasive medical insights. Samsung may lead in design polish, and Oura dominates brand awareness, but Circular is betting on depth and independence.
Availability and Pricing
The Circular Ring 2 is currently available for pre-order through the company’s official website and Kickstarter page.
Early backers can purchase it for $239, while the standard retail price is expected to be slightly higher after launch.
Each purchase includes the ring, charging dock, sizing kit, and a 1-year warranty. The device is compatible with Android 9+ and iOS 14+, ensuring broad accessibility.
Future Roadmap
Circular has already shared its roadmap for the coming year, which includes:
- Q4 2025: OTA update for blood pressure monitoring
- Q1 2026: Enhanced AI algorithms for HRV and sleep analysis
- Q3 2026: Beta release of glucose trend tracking
- Q4 2026: Expansion into smart home integrations (Alexa, Google Fit)
If Circular delivers on these updates, it could redefine what consumers expect from compact health wearables.
Expert Opinions and Market Response
Tech analysts and early testers have praised Circular’s ambition. Industry experts suggest that while accuracy validation will be key to mainstream adoption, the company’s transparent communication and engineering progress have already set it apart.
Many see the Ring 2 as a bridge between wellness gadgets and preventive healthcare tools — potentially empowering users to monitor key vitals in real time.
Even medical researchers are watching closely. If Circular’s PTT-based blood pressure tracking proves reliable, it could open doors for future medical certifications.
Final Verdict
The Circular Ring 2 isn’t just another health tracker — it’s a bold statement about the future of wearable technology.
At $239, it combines elegance, innovation, and independence, offering a subscription-free ecosystem that prioritizes user empowerment over monetization.
While the blood pressure and glucose tracking features are still on the horizon, the ring’s core performance already positions it as one of 2025’s most promising health devices. Its Kickstarter success and growing global attention further signal that users are ready for something smaller, smarter, and simpler.
For those who want to understand their body better without being tied to bulky watches or costly subscriptions, the Circular Ring 2 may just be the perfect fit — both literally and technologically
