All tubes are CNC mandrel bent for optimal flow for the J-bends in this header builder kit. Made from 304 stainless steel for maximum corrosion resistance. The diameter of tubes is 2-1/2" with .049 wall thickness. This kit includes (2) 3/8" thick CNC laser cut flanges, of your choice. Also comes with (12) J-bends, (2) formed collectors and (2) filler diamonds to connect the tubes together. We recommend the use of 308L SS welding rod. These kits are proudly made in the USA.
All warranty questions, claims or otherwise should be directed toward the manufacturer, Dart.