AEM 3.5 BAR Boost or Exhaust Backpressure sensor kit. Sensor includes pigtail wire connector and schematic. Works in conjunction with the AEM EMS. Features brass body with a 1/8 NPT threaded fitting. This sensor, along with an Intake Air Temperature sensor, is necessary to allow the AEM Engine Management System to convert your MAS metered Lancer Evo to Speed Density system.