This replacement lithium battery is designed for use with the Physio Control Lifepak CR2 defibrillators. Equipped to provide a 4 year battery stand-by lifespan, the Physio Control CR2 battery has a reserve of 6 more shocks after the defibrillator indicates a low battery warning. This gives you enough time to obtain a replacement CR2 battery ready for use. Suitable for the following Physio Control Lifepak CR2 defibrillators: Lifepak CR2 Semi Automatic Defibrillator with WiFi Lifepak CR2 Fully Automatic Defibrillator with WiFi Lifepak CR2 Semi Automatic Defibrillator with WiFi & 3G Lifepak CR2 Fully Automatic Defibrillator with WiFi & 3G