You must know this before you make your purchase! -There is no painting in this exhaust, Rust can come out over time, "solution" you applies high heat paint. -This exhaust will change color due to the high heat generated by the engine. -Loud! -Gasket & Engine not included. 1/2 SS female Threaded. 2 Lock washer and 2 nut included. 1/4" thick flange, wall heavy duty. 7.5" long (see photos for details) Stainless Steel 1/2 Female Thread Coupling... the rest of the pipe is mild steel. If you are thinking about using it as it is, keep in mind that it will be very loud! you can find one with moffler in my amazon store. Good for: Mini bikes, go karts, generators... multipurpose. Fit in the following engines: Predator 3HP 79cc from harbor freight tool (see photos for details)