No, the Polar Pacer Pro is designed to measure heart rate via the integrated optical heart rate measurement system (Polar Precision Prime) and not via an external heart rate belt. Although the Pacer Pro may be compatible with other Polar products such as the Polar H10 or H9, it is not possible to display the heart rate directly from a heart rate belt on this specific smartwatch if you are not using the integrated heart rate measurement.

However, if you want to use an external heart rate belt such as the Polar H10 or H9, you should check the compatibility and specific instructions in the Pacer Pro user manual to ensure that the connection and display of heart rate data is supported.