This is new-in-box and has not been used. I tried to return the pipes back to MRT but they were asking for a restocking fee, which was not worth the return. This will fit Mustangs 99-04 models. Email for details. Asking $450 obo. Looking to sell locally, only - unless you can cover shipping cost. MRT Stainless H-Pipe w/ Cats - New in Box Upgrade your Mustang's exhaust system to the new MRT Stainless Steel "MaxFlow" H-pipe for the '99 and up Mustangs, the only one on the market! Improve vehicle performance and change your exhaust sound to that low deep tone that H-pipes are known for! Dyno-testing shows 9 RWHP gain on a STOCK GT - more HP than a common X-pipe. This exhaust system is built from High grade Stainless steel using a computerized CNC bender for precision fitment and stainless rod welds for guaranteed years of worry free performance. Comes with all necessary hardware, plus a new OEM Manifold flange gasket! Tube Size: 2 1/2" Cats: High Quality MagnaFlow Cats