The EVO MR BOV is constructed out of Aluminum and comes with stiffer spring then the stock EVO BOV. The EVO MRBOV is capable of holding more boost than the plastic BOV commonly found in 2G DSM and EVO that often leaks during high boost applications. 

Fits: Mitsubishi Lancer Evolution 9

Tech Tip: This is a 100% bolt on BOV for your 03+ EVO, no expensive flanges are required for installation.

Tech Notes: This part is constructed of metal, the USA spec MR bov ismade of plastic. These are imported from Mitsubishi Japan