Wear the optical heart rate sensor on your arm.

Before wearing the heart rate sensor

• Secure the sensor appropriately using the arm band so that the optical sensor part makes close contact with the skin.

• If an allergic reaction or skin inflammation occurs during use, stop using immediately, and consult with a doctor.

• When the outside temperature is low, the heart rate may not be measured correctly. In these situations, use your cycling wear or other object to warm the sensor, and then perform measurement.

• This sensor cannot be used underwater.

• Strong body movements, large muscle movements, tattoos, and other factors may prevent the sensor from measuring correctly.

1. Wear the sensor on your forearm or upper arm using the arm band.

Adjust the length of the arm band, and secure the sensor in place. Overtightening the arm band may cause discomfort during measurement.

* Ensure that the optical sensor part is in close contact with your body.

* Accurate measurement may not be possible when placed on the wrist.

* A smaller arm band is available (sold separately) for those with thinner arms.

Included arm band
Perimeter : Approx. 220 − 360 mm, Applicable Diameter : ø70 − 110 mm

Small arm band (sold separately)
Perimeter : Approx. 170 − 260 mm, Applicable Diameter : ø50 − 70 mm

2. Quickly press the heart rate sensor button to turn on the sensor.

The LED indicator will turn blue, and the sensor will enter the following state.

• Flashing green and blue alternately: Detecting heart rate.

• Flashing green: Heart rate measurement is in progress.

• Flashing red and blue alternately: Heart rate measurement is not possible. Make sure the sensor is attached correctly.

* The power will not turn on if the button is pressed and held.

* If the heart rate cannot be measured correctly, try again by wearing on a different part (forearm, upper arm).

* If the indicator flashes red, the remaining battery power is 20% or less. Charge the heart rate sensor according to “1. Before use: How to charge”.

* The power will turn off automatically if no heart rate is measured for 15 minutes.

3. After measurement is complete, press and hold the button on the heart rate sensor to turn off the power.

Press and hold the button until the LED indicator turns red.