HeartSine PAD-PK 03 contains both battery and pads in one simple to replace cartridge, meaning there is only ever one expiry date and only ever one component to replace. Rather than having a large and heavy battery HeartSine have come up with the single-event pad-pak concept that is lightweight and easy to change. After an event, you have to replace the pads on any defibrillator – so it's no harder to replace a pad-pak. And this means less weight, less cost, less confusing overlapping expiring components. If you have a genuine event where you use your AED in a rescue, HeartSine will give you a replacement pad-pak free of charge (subject to some simple terms and conditions).