Note: Exhaust only works on the engines mentioned in the title and description, DOES NOT WORK ON THE DURAMAX 16 OR 18HP, DO NOT ORDER IT IF YOU HAVE THIS ENGINE, NO MATTER THAT YOU HAVE 420CC ALL THE MANUFACTURERS MAKE THEM DIFFERENT WHERE THE EXHAUST FLANGE MOUNT... This header does not have any kind of paint Uncoated Steel. ***Please read before you make your purchase*** If you are buying this for a mini bike please be sure to take measure to ensure that you will not burn your leg. All mini bike are completely different! ->> 2 bolts included and 2 washers. -Gasket included. -Engine not included. Pipe Diameter. OD: 1.25" ID: 1 1/8" Tube with 1/16 wall. This is custom made Header, weighs about 35oz. Center hollow to hollow 2" (please look all The picture for details) Remember this is not a Muffler, is loud! This been tested on 8HP (301cc) OHV predator, and Predator 13 HP (420cc) engine from harbor freight. -Works also: GX 240, 270 & 390, Briggs 1450 305cc, Lifan LF190F-BQ 15 HP 420cc Made in U.S.A.