Features Portable 3 channel ECG machine Working modes:Manual/Auto/Arrhymia Analysis modes 80mm?3channel format recording Built in rechargable Li-ion battery Adapte 110-230V,50/60Hz AC power supply Real-time ECG waveform,16 patients save/replay Built in USB/RS232 interface Feasible paper size:80 mm roll/Z-fold ECG-9031:3.8" large LCD displays working parameters and waveform ECG-9032:5.7" large LCD displays working parameters and waveform ECG archive sofeware optional