The AEM Fuel Pressure Regulator Rebuild Kit includes the Diaphragm, O-Ring and 3 Orifices for different fueling requirements. This rebuild kit works for the AEM Fuel Pressure Regulators for Hondas/Acuras (AEM Part#s 25-300, 25-301, 25-303 and 25-304), as well as our Universal Fuel Pressure Regulator (AEM Part# 25-302). If you don’t have one of these in your spares box, get one now!