The divorced and transformable 3" stainless O2 housing and downpipe assembly for 2008 and up Mitsubishi Evolution X (10) is a much higher flowing replacement for stock restrictive cast iron exhaust elbow and small diameter downpipe just before the cat. This unit bolts right up to the stock turbo and facilitates a greater amount of exhaust flow out of the turbine while reducing the amount of turbulance in the erea near the turbine wheel discharge. The result is much quicker boost response throughout all gears, big gains in torque and much higher HP all the way through redline. Even when mated to the stock exhaust system, we saw huge gains due to the increased exhaust flow. We also saw lower EGT's which above and beyond the power and torque gains, can increase reliability on the EVO X engine.This unit is constructed of a thick 1/2" CNC machined discharge flange, 304 grade stainless mandrel bent tubing, a high flow 3" stainless flex joint, and TIG welding for better appearance and durability. 02 bung is also in place for factory 02 sensor. The unit is totally optimized for flow while retaining the compactness so you can re-install the factory stock manifold heatshield.This is a must have for anyone looking to unleash all the power in a stock (or other factory location) turbocharger. We have tested this application to support well over 500HP.