With the ability to power up to 500 shocks, this replacement lithium battery is designed for use with the Cardiac Science Powerheart G5 defibrillators. Equipped to provide a 4 year operational lifespan, the Powerheart G5 battery has a reserve of 9 more shocks after the defibrillator indicates a low battery warning. This gives you enough time to obtain a replacement G5 battery ready for use. Provides power to the Cardiac Science Powerheart G5 defibrillators, Can deliver up to 500 shocks (150VE), Holds a reserve of 9 shocks after low battery warning is given, Ideal to keep as a spare when the defibrillator indicates low battery, 4 year operational lifespan This item is shipped directly from the manufacturer, please allow 7 days for delivery.