





















| SpO2 | |
| Measuring Range | 0~100% |
| Resolution | 1% |
| Accuracy | At 70~100%, ±2%; At 0~69%, unspecified |
| Data update period | <13 s |
| PR | |
| Measuring Range | 25~250 bpm |
| Resolution | 1 bpm |
| Accuracy | ±1% or ± 1 bpm, whichever is greater |
| Data update period | <13 s |
Possible Problems and Resolutions
| Problems | Possible Causes | Solution |
| There is no response to the function button. | The button can not be pressed to its position | Ensure that the button is fully depressed. |
| Battery capacities are low | The batteries may be missing, discharged, or oriented incorrectly. Replaced them with new ones. | |
| Battery installation error | Please check whether the positive and negative directions of the battery are consistent with the positive and negative directions of the battery compartment. | |
| The Pulse search time is too long | Perfusion may be too low | Check the patient. Change the measuring site. Try another oximeter. |
| Patient movement | Interference due to patient activity may be preventing the oximeter from tracking the pulse. Keep the patient still, if possible. | |
Electromagnetic interference may be preventing the oximeter from tracking the pulse. | Remove the source of interference. | |
There may be interference due to ambient light, or the oximeter may be on an extremity with a blood pressure cuff, arterial catheter, or intravascular line. | Reposition oximeter, as necessary. | |
Display is dark-or-bright | Battery capacities are low. | Replace the batteries. |


1. Please open the package and check the product after you receive the product. If you have any inquires or problems, please feel free to contact us.
2. If there are any issues, please do not hesitate to contact us through eBay Message first. Please do not rush to initiate a return request or leave a negative review. If it is a product issue, we will replace it for free. Please rest assured.
3. We will reply your email within 1 business day (except weekend). Please rest assured that we will never ignore any information.
![]() | ![]() | ![]() | |||
| SpO2/PI | ✔ | ✔ | ✔ | ✔ | ✔ |
| Heart rate | ✔ | ✔ | ✔ | ✔ | ✔ |
| OLED display | ✔ | ✔ | ✔ | ✘ (LED) | ✘ (LED) |
| Bluetooth | ✔ | ✘ | ✘ | ✔ | ✔ |
| Age recommendation | >12 Years Old | >12 Years Old | >2.5 , <12 | >2.5 , <12 | >12 Years Old |
| Finger size | Adult | Adult | Child / Kids | Child / Kids | Adult |
| Color | Grey/Black | Grey/Black | Blue/Pink | Blue/Pink | White/Black |
| Brand | HOLFENRY |
|---|---|
| Type | Fingertip Oximeter |
| Country of Origin | China |
| Power Source | Battery |
| MPN | JKS50C |
| Unit Type | Unit |
| Display Type | OLED |
| Manufacturer Warranty | 1 Year |
| Features | Smartphone Compatible, Free APP, OLED Display, Auto Shutdown, With Alarm |
| Features 2 | Bluetooth Connection |
| Labels & Certifications | FDA 510K Compliant |
| Unit Quantity | 1 |
| Color | Gray |
| Sensor Technology | Infrared Sensor |
| Model | JKS50C |
| Connectivity | Bluetooth |
| Product Line | Holfenry JKS50C Series |
| Bluetooth | pulse oximeter with bluetooth |
| Oximeter Type | Fingertip Pulse Oximeter |
| Included Probe | No Probe Included |
| Form Factor | Fingertip |
| Recommended Finger Size | oximeter pulse for Adults |

