The GE MAC 600 ECG system for recording resting ECGs can be operated as a stand-alone or portable device. For this purpose, the ECG device is equipped with a lithium battery that can record up to 250 ECGs on a single charge. The MAC 600 system is fully operational within only 7 seconds after power-on, saving valuable time. ECG data is not stored on an internal disk, but on a separate SD card, which makes data transfer to the PC particularly easy. The ECG system is available with or without external memory or SD card.