TAG, MEDICAL TRIAGE RESCUE (50/BX) The Original METTAG MT-137 provides first responders and rescue personnel with the standard triaging features needed to enable them to perform a prompt and accurate assessment of a Mass Casualty Incident The MT-137 is used extensively by U.S. military units, fire and EMT personnel, as well as a large number of federal, state and local response agencies, including the Department of Defense