The HeartStart HS1 is designed to enable anyone, even without prior training, to save lives in the event of sudden cardiac arrest. The device is intuitively activated by pressing the power button or opening the device cover, and the treatment is conducted with step-by-step voice-guided instructions, from placing the pads to the arrival of medical personnel, including CPR instructions and massage rhythm. The voice instructions are tailored to the caregiver's pace and do not move to the next step until the user is ready, or skip instructions if the actions have already been performed. It automatically detects the type of pad (adult/child) and adjusts the instructions and electrical energy accordingly. The device uses a low-energy biphasic wave to improve the chances of recovery and directly matches the patient's resistance. It performs regular self-tests to ensure its functionality, including pad, internal circuit, and battery level checks (9 volts, valid for 4 years), with a capacity of at least 200 activations or 4 hours of operation. The device comes with an 8-year warranty and is approved for use in the security system. Compact and lightweight, it is suited for carrying inside ForUrAid, ADVANCE/TACTICAL carriers.