To use the LIFEPAK CR Plus AED, you simply press the release to open the lid and the unit turns "on." It's so simple since there's no "on" or "off" button to press. Once the lid is opened, the voice prompts start talking you through the rescue process. Maintaining the Physio-Control LIFEPAK CR Plus is easy. The CHARGE-PAK (a battery system unique to the CR Plus) and electrodes ship to you with identical expiration dates. At expiration, or after each use, you replace both simultaneously. CHARGE-PAKs and electrodes last about 2 years. Pediatric electrodes are available as an option, too. Regular self-testing and a phenomenal 8-year factory warranty add up to unsurpassed reliability! The LIFEPAK CR Plus performs a basic self-check weekly and a deeper diagnostic test monthly. This means you don't have to constantly check the device's status by turning it on. The AED has a readiness display which reveals its status to you even through the carry case.