The smallest, lightest, most advanced defibrillator monitor ever made, with all the capabilities you'll ever need! The Zoll M Series is Only 11 pounds (5kg). Half the weight and a third the size of any unit in its class, the Zoll M Series Defibrillator has everything you need for cardiac resuscitation: fast, easy to use defibrillation using synchronized cardioversion, external pacing, ECG with advanced monitoring, built-in AC or DC power, and an integrated information management system.