The highly portable BTL-08 SDI ECG is similar to the SD3 model, but is a simplified version. It can however be upgraded to the SD3 model. This little ECG device features a 1-channel LCD display and provides 58 mm printouts. It can operate either of batteries of from a power outlet. Manual, automatic, or user-defined profiles can be accessed by means of the alphanumeric keyboard. The display features a loose-lead indication and also signals the presence of a pacemaker.