The Philips HeartStart OnSite defibrillator is designed to enable you to help save a life in extraordinary circumstances. Its clean design and clear voice instructions instill the confidence you need when administering therapy to a person in cardiac arrest. Powered by a long-life disposable battery, the HeartStart OnSite tests itself regularly to ensure readiness. Can be used on persons of any age including infants and children. And most important, it’s effective. Its patented SMART Analysis heart rhythm assessment and SMART Biphasic defibrillation therapy are clinically proven in over 10 years of use.