The electrocardiograph (abbreviated as EKG or ECG) is a device that records surface potentials associated with the electrical activity of the heartbeat. The surface potentials are conducted to the device by metal contacts called electrodes which are fixed to various parts of the body. Usually, the electrodes are attached to the four limbs and over the heart. Easy, smart, Fast, and High quality. 2 ways of print system with roll paper and Z-fold. 500 cases of internal data storage. Li-ion ​rechargeable battery capable 2 hours of operation, about 200 printouts. 8,000 samples per second.