How it Works

First time using YONO? The YONO package contains a base station, earbud, one set of ear tips with three different sizes and a USB charging cord. Follow our step-by-step instructions and watch the instructional video to get started. 


Choose your size

Put the YONO earbud in either one of your ears; experiment with each of the three tips. Change the size of the ear tip if you feel it is too tight or too loose.

Charge the base

Make sure the earbud is placed in the center of the base station, and the lid of the base station is pressed down and locked. When YONO earbud is fully charged, the green LED light flash quickly intermittently.

Download the app

Download the YONO application for iOS on your smartphone. Please sign in and use the YONO fertility app to record your information.


Connect the device

Don't pair the earbud with your phone before wearing it. Wear YONO in your ear for about 10-15 minutes, put the earbud back on the base station and connect with your phone.

Using YONO

Take the YONO earbud out of the base station and put it into your ear (preferably the ear on which you will not be laying for an extended period of time). Upon awaking, put the YONO earbud back into its base station. The base station lid must be pressed down and locked to guarantee data transmittal. If the lid of the base is not closed, the pogo-pin will not be connected. A solid blue LED light will appear, indicating the device is broadcasting for Smartphone Bluetooth connection. Open the YONO application, click the “Analysis” icon (right upper corner) and then click the “Connect” icon (right upper corner). The smartphone screen will display “Connecting,” the YONO base station will begin to flash and the display will soon change to “Connected.” Data transmission is complete when the blue LED light disappears. You now have your last night’s temperature data programmed into your smartphone.

Care & Maintenance

If the red LED light turns on when returning the YONO earbud to the base station, it needs to be charged.  To charge, connect the YONO base station to the USB cord. When a green LED light flashes, the device is being charged. When the earbud is fully charged, the green LED light will flash quickly but intermittently. We suggest charging each morning so you start the night fully charged and ready to go! The YONO earbud is not waterproof. You can’t wear the YONO during a shower or immerse the earbud in water to clean. To replace any size ear tip, simply order a new one on our website. Please watch the following instructional video on how to clean your YONO in-ear thermometer.

Precautions & Warnings

Please note:

  • Using the YONO may cause discomfort in the ear canal or to the skin; if this is the case, discontinue use.
  • Stop using the YONO earbud if you have discharge, infection or any other ear issue and see a doctor if necessary.
  • Keep children away from the YONO earbud and base station.
  • The device belongs in the ear only.
  • Keep the base lid clean and closed at all times.
  • The YONO Earbud is not intended to monitor fever, or any other medical use.

Troubleshooting & Tips

For any problems connecting the device or transmitting data, please remove the earbud from the base station, and put the earbud back to the base station, close the lid firmly, and try connecting again. 

Attention: DO NOT try to reset your device by using a toothpick or anything else to hit the reset button at the bottom of the base station.

  • BLUE Solid: Broadcast for Bluetooth connection.
  • BLUE Flash: Data transmission.
  • BLUE Off: Data transmission completed.
  • GREEN Speed Flash Three Times: Earbud is fully charged.
  • GREEN Slow Flash: Earbud is being charged.
  • No Light On: Out of battery, please charge device.

Note: When the earbud is fully charged and taken out of the base without the USB plugged in, no LED light will display. The LED light might remain if the charging is not complete.