This defibrillator and monitor is designed to meet your resuscitation and monitoring needs. The HeartStart XL is lightweight, portable, and a semi-automatic external defibrillator. It offers two modes of operation; Automated External Defibrillation (AED) Mode and Manual Mode. Both modes incorporate low energy SMART Biphasic waveform for defibrillation. When in AED mode, the HeartStart analyzes the patient’s ECG and advises you whether or not to deliver a shock.