Swimming with Polar M400?
Polar M400 is water resistant and good for tracking activity when you swim, but it can't record heart rate in water. That is because the Bluetooth Smart used for transmitting data does not work in water.
Polar M400 is water resistant and good for tracking activity when you swim, but it can't record heart rate in water. That is because the Bluetooth Smart used for transmitting data does not work in water.