The Perrin Performance Subaru Impreza WRX & STi short ram intake system features an aluminium MAF sensor housing, silicone hose from the turbo inlet to MAF housing, mounting bracket, and high-flow dual-stage foam air filter. Perrin's Impreza WRX & STi short ram intake uses proper MAF sizing and placement to optimize power, maintain safe air/fuel ratios, and extract as much power as possible. The Perrin Subaru WRX & STi short-ram intake can be converted to a cold-air intake using the optional Perrin Cold Air Extension, sold separately. Perrin's dual-stage foam air filter can be recharged using the Perrin filter cleaning kit, sold separately.