Brand: Physio Control - USA Model: LIFEPAK CR 500 AED Part Number: 81401-000011 The rugged Physio-Control LIFEPAK 500 AED Defibrillator is one of the most popular and most deployed AEDs ever made! Hundreds of thousands of these devices are in use all over the world. Physio-Control, a division of Medtronic, and LIFEPAK are legacy names in emergency defibrillation. The Physio-Control Lifepak 500 is a portable, battery-powered automated external defibrillator. Once the Electrode pads are attached to the patient, the defibrillation system can evaluate the heart rhythm and detect if a shock is needed. The Physio-Control Lifepak 500 comes in both Monophasic and biphasic modes. The Lifepak 500 is an AED that offers both vocal and visual step-by-step instructions on how to use the defibrillator. The two-button operation system makes it easy to use, with an on/off button and a shock button. Like most defibrillators, the Lifepak 500 runs a self-test every 24 hours making sure the system is running properly and is ready when needed.