Engine not included. -2 Lock washer and 2 nut included. 1/4" thick flange, 1/8 tubing wall heavy duty. 13.50" long (see photos for details) -Pipe Diameter. OD: 26.86mm ID: 21.70mm High Quality -center hollow to hollow 1" 13/16 Please check the pictures for measures and details before you buy it! Remember this is not a Muffler, it make a lot of noise when it accelerates! This Header is made especially for mini bikes! but also works in go kart. Weighs about 35oz This been tested on Predator 212cc (6.5hp) Predator Hemi, GX160, GX200. also tested on Powerhorse 208cc, DuroMax 7 Hp, 212cc Tillotson Hemi (no tested on other engine) Made in U.S.A.