This LIFEPAK CR Plus Replacement Kit contains the following items: One CHARGE-PAK charging unit; one set of QUIK-PAK pacing/defibrillation/ECG electrode pads; one CHARGE-PAK discharger which is used to safely deplete a used CHARGE-PAK prior to disposal or recycling; and replacement instructions. The LIFEPAK CR Plus AED electrode pads and battery/charger are sold only as a kit and are not available as a separate orderable item, and both the battery/charger and defibrillation electrode pads are replaced simultaneously either upon use or expiration; the expiration date of both components in this kit is exactly the same. The LIFEPAK CR Plus AED functions slightly differently from other AEDs; instead of a battery, it uses the CHARGE-PAK battery system which charges an internal, permanent battery inside the AED device. After an AED use or about two years (whichever comes first), the battery charger and electrode pads both need to be replaced.