Gibson Performance Exhaust Systems are the perfect solution for your vehicle if you're looking to add a little style, sound, and horsepower to your vehicle. Gibson Exhausts are true bolt-on systems that look and sound great. Because the factory mounting points are utilized, there is no welding or guess work. Simply unbolt your boring and inefficient factory exhaust system and your new Gibson Performance Exhaust bolts into place. All Gibson Exhaust Systems are dyno tested to assure increased horsepower and produce more torque before they are released to the public. All exhausts are mandrel bent to minimize exhaust restriction. Average horsepower and torque gains are 10-15 range on stock (unmodified) vehicles, and even higher numbers for vehicles running other aftermarket performance parts. Gibson Exhaust Systems carry a limited lifetime warranty from the manufacturer. The part number for this item is Gibson 65676 and it fits 2015-2017 GMC Yukon XL 1500 (6.2 V8 Only) models. This exhaust features a 3.5" diameter that splits due dual 2 1/4" Diameter and DUAL 4" Tips, one exiting on each side of the vehicle behind the rear tires.. This is a Cat-Back exhaust, meaning all piping behind the cat is replaced.