Electrode pads for Physio Control Lifepak AED defibrillators. The CRexpress and CRplus AED models use a electrode set that incorporates a battery as well. These spare parts should be replaced all together. The Lifepak 1000 and Lifepak 500 models use the Quick Combo electrode pads set. For all the Physio Control AEDs there are child pads available.