These defibrillation electrodes are for the Philips HeartStart FRx AED. They're packaged in a plastic case, which fits into the FRx semi-rigid carry case. Like other AED pads, SMART Pads II are one-time use and disposable. Order an extra set to keep your FRx AED ready for action and make sure you keep an eye on the expiration date printed on each electrode pad set. SMART Pads II have an expiration date of at least 24 months from date of manufacture and need to be replaced when they expire to keep the AED in working order.