This award-winning AED has been designed so that virtually anyone can use it to help save the life of a person who suffers a sudden cardiac arrest. Clear, calm voice instructions talk you through each step. The HeartStart Home AED senses and adapts the instructions based on your actions. Using sophisticated technology, the HeartStart Home AED quickly decides whether a shock is necessary. The AED is designed to only deliver a shock if needed. It will even coach you through the steps of CPR. Like other essential safety equipment, you buy the Philips HeartStart Home AED hoping that you never have to use it. Yet in that moment you need it, the HeartStart Home AED must be ready.