Sudden cardiac arrest strikes millions of people a year worldwide with no warning and no pattern. Immediate treatment is vital. A victim's chance of survival dramatically decreases for every minute without treatment. This means an automated external defibrillator (AED) must be close at hand, easy to use and ready to shock. It's the first choice in an AED service program because of its durability and simplicity to service. It uses the practical Pad-Pak, which incorporates the batteries and electrodes in a single-use cartridge—meaning only one expiration date to monitor and only one item to replace after use.