Elizabeth Fire Department (Union County NJ) EMS 77. This rig is known as MAB (Mobile Ambulance Bus) 1 throughout the state. This rig is a 2012 42' Thomas Bus Up-Fitted by Sartin Services. MAB’s are used to provide basic medical support, evacuation, and transportation services and can be used to import personnel and/or equipment and supplies into areas of need. There are 19 MAB’s in NJ and they are purchased through the Homeland Security and are operated through the NJ UASI team.