RV6 2012-2015 Civic SI Bellmouth Downpipe with Metallic HFC KitWhen the K24Z3 was first introduced, many people were disappointed with the integrated exhaust manifold that made conventional "headers" obsolete. This is especially true since the K Series platform produced some very impressive performance gains with quality headers. Specifications: 304 Stainless cast flange sections 304 Stainless 2. 5" tubing 300 Cell High Temperature Cat TIG welded Argon back gassed for pure welds Includes: 3 X M10 1. 5 Bolt Set 1