To facilitate training on the Philips HeartStart OnSite AED, Adult (M5073A) and Infant/Child (M5074A) Training Pads Cartridges are available. These special purpose pads, when installed in the HeartStart OnSite, suspend the defibrillator's ability to deliver a shock and activate its training mode, enabling the user to run any of eight emergency scenarios. Depending on which cartridge is used (Adult or Infant/Child), the defibrillator's voice instructions, including cardiopulmonary resuscitation (CPR) coaching, will be appropriate for treating the simulated victim.

Each training pads cartridge consists of a removable clear protective lid with a handle, a resealable film cover, and a pair of reusable adhesive pads. It is packaged with a Pads Placement Guide (either Adult or Infant/Child) and illustrated instructions for installing the cartridge, using the Pads Placement Guide, and repackaging the cartridge after using it. A training pads cartridge can also be used on a manikin, connected with an internal (M5088A) or external (M5089A) manikin adapter.