... Modes (3)Alphabetic keyboard for patient information (1)Portable 12 channel ECG machine(2)Manual/Auto/Arrhythmia Analysis Modes(3)Alphabetic keyboard ... 110-230V,50/60HZ AC power supply(6)Real-time ECG waveform,cases save/replay(7)Built in USB/RS232 interface ... printerSafety standard:GB9706.1-2007,IEC Class I,Type CF ECG machine twelve channel