The Infant/Child electrodes are designed for use on a child less than 8 years old, or weighing less than 55 lbs. These pads will deliver an age/weight appropriate energy dose. The pads are compatible with the LP500*, CR Plus, Lifepak 1000, and Express. *The LIFEPAK 500 AEDS can use these infant/child pads if they have the pink inner lining connector as opposed to other LIFEPAK 500’s with the gray/black connector (the gray/black connector AED can be upgraded and then can use the infant/child electrodes.)