Medco Aspirator IV The Medco Aspirator IV utilizes two advanced, state of the art positive displacement pumps. These dual headed pumps relieve back pressure to allow each individual pump to pull against the patient so that a deep vacuum is quickly reached and maintained. If one pump should go down, the other three will continue to function independently. The positive displacement pumps used in MEDCO Aspirators are the quietest on the market. The aspirator is made even quieter with 1” shock mounts to eliminate vibration. This, combined with a super quiet muffler and insulation system, make the MEDCO Aspirator IV the QUIETEST aspirator on the market today. All Medco Aspirators come with a limited 5 year warranty on all parts and labor.