... size with thermal printer standard 12 leads digital three channel ECG machine BS-306BFEATURES3 channel ECG machine with measurementManual/Auto/Arrhythmia Analysis Modes80mm ... Adapt to 110-230V,50/60HZ AC power supplyReal-time ECG waveform,cases save/replayBuilt in USB/RS232 interface(ECGNET ... 5,5,10,20,40mm/mVRecorder:High resolution thermal printer digital three channel ECG machine with 5.7" screen