During sudden cardiac arrest emergencies, saving time saves lives. The Philips HeartStart OnSite uses SMART pad Cartridges are pre-connected for even faster deployment. As soon as you pull the green cartridge handle the device activates and begins coaching the rescue step-by-step. SMART pads come ready to be peeled off immediately and placed directly on the patient. The Philips SMART pads Cartridge are only compatible with the Philips HeartStart OnSite and Philips HeartStart OnSite Home Unit, and cannot be used with any other Philips AED models. SMART pads cannot be used as training pads. For AED training purposes, purchase an OnSite SMART Training pads Cartridge which is compatible with your OnSite AED.