You must have a Mishimoto Air Intake (Sold Separately) in order to use this item. If you're looking to add some extra performance and style to your existing Mishimoto Performance Intake, this air box ia a great idea! Made from durable steel and featuring a gloss black powder coat, this Mishimoto Air Box will help stabilize airflow and enclose your air filter, protecting it from heat and increasing horsepower and torque. The part number for this item is MMAB-WRX-01 and it fits 2001-2007 Subaru WRX / STI models that already have a Mishimoto Air Intake System.