The Polar H10 sensor is placed on the body.

Polar H10 Heart Rate Sensor – The Gold Standard Of HR

Polar H9 Bluetooth, ANT+ and 5 kHz Coded Heart Rate Sensor

Polar H10 review: Connected heart rate monitoring with a catch

Polar H10 Heart Rate Sensor Review: Accurate and Comfortable

Connect your Polar H10 to Galaxy watch 4/5. This is how one can do using Google Fit & sync it to Samsung Health. : r/GalaxyWatch

Polar Heart Rate Tracking WithThe Verity Sense And H10 Sensors - Motorcycle News

Heart Rate Sensors: Polar Verity Sense vs Polar H10 and Polar H9

Polar H9 Training with Polar H9 and Polar Beat

Polar Verity Sense Optical Heart Rate Sensor - Better Body Sports

Polar Verity Sense Optical Heart Rate Sensor - Gopher Sport

My H9 heart rate strap keeps getting sweat on the contacts and bugs out : r/Polarfitness