Kit includes a selection of prefabbed 1.75" O.D., 16-gauge rolled steel tubing, header flanges and exhaust tips that puts the art of custom exhaust building in the hands of backyard fabricators Each kit includes; two 16" long straight sections, two 3.5" radius U-bends with straights, two 5" radius U-bends with straights, two each of Evolution, Shovelhead, Ironhead and STD flanges and two fishtail tips All raw tube sections are pre-polished to make chroming after joint finishing easier