Features: 14.4cm (5.7″) STN Blue LCD with backlit display. Non-fade sold traces of graphical ECG waveform on the LCD Screen. Real-time ECG on the first channel and frozen / delayed ECG on the Second channel. Auto ECG freeze on the alarm condition. 1mV calibration pulse indicator. LED blinking for every detected QRS complex. Standard frequency response and high common mode rejection ratio. Built-in rechargeable battery.