Open the lid. The AED powers on automatically and begins voice prompts. Expose the patient's chest, peel the CPR-D-padz from the foil pouch, and apply them in the positions shown on the pad illustrations (one upper right chest, one lower left side). The AED analyzes the heart rhythm and announces "Shock advised" or "No shock advised." If shock advised, the semi-automatic model prompts you to press the orange button; the fully automatic model delivers the shock after a 3-second countdown. After the shock, the unit guides you through CPR with real-time compression depth feedback. For complete training, see our AED trainer catalog.