Difference Between ECG Sensor Bitalino & ECG Sensor Biosignalsplux?

ECG Sensor Bitalino (Bitalino has 12 bit sampling rate):

ECG Sensor Biosignalsplux (Biosignalsplux has 16 bit sampling rate):

The wires to the ECG electrodes of the Biosignalsplux ECG sensor are very short. Are they long enough for a correct ECG placement?

The two devices have different sampling rates. But do they not use the same sensors?