Sleep Wearable Form Factor
Compare smart rings, fitness bands, and smartwatches for overnight sleep tracking: comfort, battery habits, and sleep metric depth.
Senbono HK21 Smart wearable device
If you are interested in more details, you can find full information on the seller's page.
€53.71
Last price update: 10/20/26
Available to order
Shipping options
Delivery to 
United States
United States
Available
Product details
Features
- IP67 waterproof rating
- 260 mAh battery; about 25–30 days standby time and about 5–7 days using time
- Magnetic charging; charging time about 3–4 hours
- Compatible with Android 4.4 and above and Apple iOS 9.0 and above
- Full-touch operation and BT5 3 Bluetooth
- Health monitoring includes heart rate, blood pressure, blood oxygen (SpO2), blood glucose measurement, sedentary reminders, and sleep monitoring
- Multiple sports modes; calorie, distance, and step counting
- Bluetooth calls, call and message reminders, and app notifications
- Music and camera controls, alarm clock, stopwatch, weather, custom dial and dial market, brightness adjustment, find phone, and do not disturb mode
- App: Co Fit
- 2.01-inch AMOLED display with 240 × 296 pixel resolution
SENBONO HK21 is a smart wearable device with a 2.01-inch AMOLED display, IP67 waterproof rating, and a 260 mAh battery. Reported time figures are about 25–30 days on standby, about 5–7 days using time, and about 3–4 hours charging time.
General specs
- Brand: Senbono
- Model: HK21
- Seller: Banggood
- ID: 2015219
- Brand: SENBONO
- Display: 2.01-inch AMOLED
- App Name: Co Fit
- Model Name: HK21
- Using Time: About 5–7 days
- Model Number: HK21
- Product Type: smart wearable device
- Standby Time: About 25–30 days
- Charging Time: About 3–4 hours
- Charging Type: Magnetic charging
- Operating Mode: Full touch
- Other functions: Music control; camera control; alarm clock; stopwatch; weather; custom dial and dial market; brightness adjustment; find phone; do not disturb mode
- Battery Capacity: 260 mAh
- Bluetooth Version: BT5 3
- Waterproof Rating: IP67
- Display Resolution: 240 × 296 pixels
- Activity tracking features: Multiple sports modes; calorie, distance, and step counting
- Health Monitoring Features: Heart rate monitoring; blood pressure monitoring; blood oxygen (SpO2) monitoring; blood glucose measurement; sedentary reminder; sleep monitoring
- Compatible Operating Systems: Android 4.4 and above; Apple iOS 9.0 and above
- Notifications and call features: Bluetooth call; call reminder; message reminder; app notification
- First listed by seller: October 20, 2026
Similar products comparison
| This item | Recommendations | |||||
|---|---|---|---|---|---|---|
Senbono HK21
|
Senbono NY39 Full-touch operation
|
Senbono HK08 Bluetooth 5.3
|
Senbono AK87
|
Senbono TG02
|
Senbono D16 2.01-inch TFT IPS screen, 240 × 296 pixels
|
|
| Brand | Senbono | Senbono | Senbono | Senbono | Senbono | Senbono |
| Model | HK21 | NY39 | HK08 | AK87 | TG02 | D16 |
| Price | €53.71 | €25.57 | €59.68 | €52.86 | €42.63 | €43.05 |
| Seller | Banggood | Banggood | Banggood | Banggood | Banggood | Banggood |
| Update | Oct 26, 2026 | Oct 26, 2026 | Oct 26, 2026 | Oct 26, 2026 | Oct 26, 2026 | Oct 26, 2026 |
| Display | 2.01-inch AMOLED | 1.43-inch AMOLED; 466 × 466 pixels | 2.01-inch TFT IPS screen; 240 × 296 pixels | |||
| App Name | Co Fit | Da Fit | Da Fit | |||
| Model Name | HK21 | NY39 | AK87 | D16 | ||
| Using Time | About 5–7 days | About 5–7 days | About 5–7 days | About 5–7 days | About 7–10 days | About 5–7 days |
| Model Number | HK21 | NY39 | HK08 | AK87 | TG02 | D16 |
| Product Type | smart wearable device | Smart wearable device | Smartwatch | Smart wearable device | Smart wearable device | Smart bracelet |
| Standby Time | About 25–30 days | About 25–30 days | About 25–30 days | About 90 days | About 25–30 days | About 25–35 days |
| Charging Time | About 3–4 hours | About 3–4 hours | About 2–3 hours | About 2–3 hours | About 2–3 hours | About 2–3 hours |
| Charging Type | Magnetic charging | Magnetic charging | Magnetic charging | Magnetic charging | Magnetic charging | Magnetic charging |
| Operating Mode | Full touch | Full touch | Full touch | Full touch | ||
| Other functions | Music control; camera control; alarm clock; stopwatch; weather; custom dial and dial market; brightness adjustment; find phone; do not disturb mode | Information, call, message, and app notifications; sedentary reminder; exercise recording and multiple sports modes; calorie, distance, and step counting; music and camera control; alarm clock; stopwatch; weather; custom dials and dial market; brightness adjustment; find phone; do not disturb mode | Call, message, and app notifications; music control; camera control; alarm clock; stopwatch; weather; custom dial and dial market; brightness adjustment; find phone; do not disturb mode; strong flashlight | |||
| Battery Capacity | 260 mAh | 250 mAh | 530 mAh | 1000 mAh | 500 mAh | 350 mAh |
| Bluetooth Version | BT5 3 | BT 5.3 | BT 5.2 | BT5.2 | BT 5.3 | |
| Waterproof Rating | IP67 | IP68 | IP68 | IP68 | ||
| Compatible Operating Systems | Android 4.4 and above; Apple iOS 9.0 and above | Android 5.0 and above; Apple iOS 10.0 and above | Android 7.0 and above; Apple iOS 12.0 and above | Android 5.1 and above; Apple iOS 9.0 and above | Android 5.0 and above; Apple iOS 9.0 and above | Android 4.4 and above; Apple iOS 9.0 and above |
| Band Material | Environmental silicone | Silicone, leather, or steel | Silicone | Silicone | ||
| Watch case material | PC ABS | Zinc alloy and tempered glass | Zinc alloy | Plastic | ||
| Health-function limitation | The health test function is for reference only and cannot be used for medical purposes; the device is non-medical equipment. | Health test function is for reference only and cannot be used for medical purposes; the product is non-medical equipment | The health test function is for reference only and cannot be used for medical purposes; the product is not medical equipment. | |||
Senbono HK21
€53.71
When this device makes sense
Product confidence
Reviews
There are no text reviews yet. If you have experience using this product, please leave a review. It will help other people decide whether this product is right for them.