" indicate the difficulty level for installing the product.Built with patented Doublewall Technology, the 2.5" American Classic Straights are totally new. The 2.5" diameter outer pipe gives your bike a stout look. Designed for the serious rider looking for the right exhaust. Classics use a 1.75" inner pipe with a 2.5" outer pipe. The 2.5" American Classic Straights feature new straight cut ‘Hard-Tips’, billet end caps as standard equipment. Optional slash-cut and tapered end caps are sold separately. And at $414.95 the price cannot be beat.