MUGEN POWER HIGH PRESSURE RADIATOR CAP This high quality radiator cap functions to increase the pressure inside the radiator so that even if the water temperature exceeds 100 degree C, boiling will be avoided. Stock Honda radiator caps are rated at 1.1 BAR (1.1kg/cm2). The Mugen radiator cap increases the pressure to 1.35 BAR (1.35kg/cm2), thereby improving overall cooling performance. Fits: Acura RSX 2002 - 2007 Acura TSX 2005 - 2007 Honda Civic 1992 - 2009 Honda Del Sol 1993 - 1997 Honda Fit 2006 - 2009 Honda S2000 2000 - 2006 And other Denso style radiators