One-piece pre-connected electrode pads are easy to use, making it easy to get help to the victim quickly. One-piece pads are easing to place, using CPR hand placement as a guide. Pads have a 5-year shelf life. Designed to work with ZOLL? AED Plus? Defibrillators (sold separately). Size (W x L): 9 x 9; Weight: 1; Shelf Life: 5 years.