Perrin Alternator Pulley Red Subaru STI 2007-2021 | PSP-ENG-119RD Vehicle Model_Mazdaspeed MX-5 Miata these are replacement units

these are replacement units

it’s a must have for high boost

Balanced during the machining process to ensure optimum performance on initial fitment

32 levels of damping adjustment

Perrin Alternator Pulley Red Subaru STI 2007-2021 | PSP-ENG-119RD Vehicle Model_Mazdaspeed MX-5 Miata these are replacement unitsUpgrade your Subarus charging system and performance with the PERRIN Alternator Pulley for EJ Engines. Designed specifically for the 2007 2021 Subaru STI, this precision CNCmachined pulley reduces rotational mass while maintaining OEM belt compatibility. Key Benefits & Features Reduced Rotational Mass: At just 0. 116 lbs, this pulley is significantly lighter than the stock alternator pulley (~0. 393 lbs), improving throttle response and overall engine