Smooth tube muffler, Made from 304 stainless steel for maximum corrosion resistance. This muffler has 3" ID center inlet / outlet with a 2-1/2" core and with an overall length of 24" with a mill finish. Stainless Works is the only manufacturer to make the body, core, and packing 304 stainless steel. Exclusive louvered core creates a sweet "Street Rod" deep tone that is not overly aggressive. These are TIG welded for strength and durability. These kits come with a lifetime warranty and proudly made in the USA.