We have sold close to 100 of these kits! They fit great, control boost very well, and make over 800hp with ease! Our manifold features o2 and waste gate locations that are optimum to controlling boost, and not burning up o2 sensors. This is a very hard feat to accomplish as anyone knows and reads the forums, N54s love to kill o2 sensors. The manifold is 100% stainless steel construction and is extremely durable. The manifold fits either Tial 38mm MVS or turbo smart 40mm gates. The downpipes fits either Garrett or Precision turbos. The hot parts kit includes a charge pipe, and water pipe as well.