The Pad-Pak system is unique to HeartSine and saves you in many ways. Firstly it contains both battery and pads in one simple to replace cartridge. So there is only ever one expiry date and only ever one component to replace. We notify you prior to the 4 year expiry. Rather than have a large and expensive (and heavy) battery in a device that may never be used but costs you a lot to replace the battery, HeartSine have come up with the single-event pad-pak concept. After an event you have to replace the pads on any defibrillator – so its no harder to replace a pad-pak. And this means less weight, less cost, less confusing overlapping expiring components. And if you have a genuine event, we will give your replacement pad-pak free (subject to some simple terms and conditions).