This Lithium Manganese Dioxide Battery is designed for use in the Philips HeartStart FR2+ Defibrillator. The battery is designed to last 4 years from the date it is installed, and the “”Install by”” date is printed on the battery for easy reference. Use of HeartStart, its training cartridges, additional battery insertion tests or exposure to harsh environments may shorten the battery life. One per package. No recharging needed.