R100 Smart Ring – BT 5.3, IP68, HRV, Heart Rate, Sleep, Blood Oxygen
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Ring Sizing Guide
Example: UK size P is equivalent to US size 8. For a smart ring, order US size 9.
How to measure your finger
- Wrap a strip of paper or thin string around the base of your intended finger.
- Mark where it overlaps, then lay flat and measure the length in millimetres — this is your inner circumference.
- Find your UK size in the table below, read across to your standard US size, then order the smart ring size in the final column.
Measure in the evening when fingers tend to be at their largest. Your dominant hand is usually half a size larger than your other hand.
UK to US conversion — smart ring order sizes
| UK Size | US Size | Circumference | Smart Ring — Order |
|---|---|---|---|
| J | 5¼ | 45.3 mm | US 6 |
| K | 5½ | 46.0 mm | US 6 |
| L | 6 | 46.8 mm | US 7 |
| M | 6½ | 47.5 mm | US 7 |
| N | 7 | 48.3 mm | US 8 |
| O | 7½ | 49.0 mm | US 8 |
| P | 8 | 49.8 mm | US 9 |
| Q | 8½ | 50.5 mm | US 9 |
| R | 8¾ | 51.3 mm | US 9 |
| S | 9½ | 52.8 mm | US 10 |
| T | 9¾ | 53.5 mm | US 10 |
| U | 10¼ | 54.3 mm | US 11 |
| V | 10¾ | 55.0 mm | US 11 |
| W | 11¼ | 55.8 mm | US 12 |
| X | 11¾ | 56.5 mm | US 12 |
| Y | 12¼ | 57.3 mm | US 13 |
| Z | 12¾ | 58.0 mm | US 13 |
If you are between sizes, order the larger size — a slightly loose ring is easier to remove and more comfortable to wear throughout the day.
The R100 is a smart ring in 314 stainless steel. Weight: approximately 3.2g. Thickness: 2.6mm. Sizes: #8 (18.2mm inner diameter) through #13 (22.2mm). Bluetooth: 5.3. Waterproof rating: IP68. CPU: AB2026B3. Heart rate sensor: HX3918. Memory: 4Mb ROM, 96Kb RAM. Ring battery: 18mAh. Battery life: approximately 6–8 days normal use, approximately 15 days standby. Charge time: less than 60 minutes via charging case. Operating temperature: 0–50°C. App: Da Rings. GPS: app-based (mobile phone GPS). Health tracking: activity, sleep, exercise records, heart rate, blood oxygen saturation, HRV, stress, and female menstrual cycle. Certifications: CE-RED, CE-RoHS, FCC-ID. Colour: not specified by name in source (ColorStyle G). Package: ring, charging case, charging cable, and English user manual. Curated by Aetheo.
Why you'll like it
- HRV, heart rate, blood oxygen, stress, and sleep monitoring via Da Rings app
- 18mAh battery — approximately 6–8 days normal use, less than 60 minutes to charge
- IP68 waterproof — 314 stainless steel, approximately 3.2g, 2.6mm thick
- Bluetooth 5.3 — AB2026B3 CPU with HX3918 heart rate sensor
- CE-RED, CE-RoHS, and FCC-ID certified
Designed for comprehensive health and activity tracking
The R100 connects to the Da Rings app via Bluetooth 5.3 to record and display health metrics tracked continuously through the ring's sensors. The HX3918 optical sensor monitors heart rate and supports HRV (Heart Rate Variability) and stress tracking — metrics derived from heart rate signal data recorded throughout the day and overnight. Blood oxygen saturation (SpO2) is recorded alongside sleep monitoring, which tracks sleep patterns and records exercise data. Female menstrual cycle tracking is also supported via the Da Rings app. Activity tracking records steps and movement data. GPS function uses the paired phone's GPS — the ring does not contain a built-in GPS module. The R100 is waterproofed to IP68 and weighs approximately 3.2g at 2.6mm thickness, available in sizes #8 through #13. The 18mAh battery provides approximately 6–8 days of normal use or approximately 15 days of standby, with a charge time of less than 60 minutes from the included charging case. Certifications: CE-RED, CE-RoHS, FCC-ID. Curated by Aetheo.
Key features
HRV, heart rate, blood oxygen, stress, and sleep tracking via Da Rings
The R100 uses the HX3918 optical sensor to monitor heart rate and collect the signal data used to calculate HRV (Heart Rate Variability) and stress scores — both of which are derived from heart rate variability measurements. Blood oxygen saturation (SpO2) is monitored and recorded through the Da Rings app. Sleep monitoring tracks sleep patterns and provides sleep data via the app. Exercise records and activity tracking are supported. Female menstrual cycle tracking is available through the Da Rings app. All health monitoring data is displayed through the Da Rings app — the ring records and transmits sensor data; the app provides the display, history, and reporting interface. Health tracking features record and display data; they do not diagnose, treat, or replace medical devices or professional medical advice.
IP68 waterproof — 314 stainless steel — approximately 3.2g, 2.6mm thick
The R100 is made from 314 stainless steel with an IP68 waterproof rating — suitable for submersion in water during daily activities. Submersion depth and duration limits for IP68 should be verified with the product documentation. Weight is approximately 3.2g and thickness is 2.6mm — designed for all-day wear. Sizes are available from #8 (18.2mm inner diameter) to #13 (22.2mm inner diameter). Operating temperature range is 0–50°C. CPU is AB2026B3 with 4Mb ROM and 96Kb RAM. The HX3918 optical sensor is positioned on the inner surface of the ring for continuous skin contact during wear.
Bluetooth 5.3 — Da Rings app — 18mAh, 6–8 days battery
Bluetooth 5.3 connects the R100 to paired smartphones for data sync and notifications. The Da Rings app is the companion application for all health data display, history, and ring configuration — download and set up Da Rings before use. GPS is app-based — the ring uses the paired phone's GPS rather than a built-in GPS module. The 18mAh battery provides approximately 6–8 days of normal use or approximately 15 days of standby per charge. Charge time is less than 60 minutes via the included charging case and charging cable. Colour is not specified by name in source documentation (ColorStyle G).
Best for
- Comprehensive health monitoring — HRV, heart rate, SpO2, stress, sleep, menstrual cycle
- IP68 waterproof daily wear — 3.2g, 2.6mm, sizes #8–#13
- Extended battery life — approximately 6–8 days normal use per charge
- Da Rings app — activity records, exercise tracking, health history
- CE-RED, CE-RoHS,
Frequently asked questions
How long does the battery last on a single charge?
Approximately 6–8 days with normal use, or around 15 days on standby.
Is the R100 waterproof?
Yes, it has an IP68 waterproof rating and is suitable for submersion in water.
What health metrics does it monitor?
It tracks heart rate, blood oxygen saturation, HRV, sleep, stress, activity records, and menstrual cycle data via the Da Rings app.
How do I charge the R100?
It charges via the included charging case in less than 60 minutes using the supplied charging cable.
| Specification | Details |
|---|---|
| Model | R100 |
| Material | 314 stainless steel |
| Bluetooth Version | 5.3 |
| CPU | AB2026B3 |
| Heart Rate Sensor | HX3918 |
| Memory | 4Mb ROM + 96Kb RAM |
| Ring Battery | 18mAh |
| Battery Life (normal use) | Approx. 6–8 days |
| Battery Life (standby) | Approx. 15 days |
| Charge Time | <60 minutes (via charging case) |
| Weight | Approx. 3.2g |
| Thickness | 2.6mm |
| Sizes | #8 (18.2mm) – #13 (22.2mm) inner diameter |
| Waterproof Rating | IP68 |
| Operating Temperature | 0–50°C |
| Companion App | Da Rings |
| GPS | App-based (phone GPS) |
| Health Tracking | Activity, sleep, exercise records, heart rate, blood oxygen (SpO2), HRV, stress, female menstrual cycle |
| Colour | Not specified in source (ColorStyle G) |
| Certifications | CE-RED, CE-RoHS, FCC-ID |
| Included | Ring, charging case, charging cable, English user manual |
A Closer Look
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