If you're looking for the best-flowing, meanest sounding exhaust system in the business, this is it! SLP's legendary Loud Mouth System employs a specially designed resonator instead of a traditional muffler, allowing them to offer unmatched power increases and a wicked ''wide-open'' sound. Gains of up to 25 horsepower are possible, depending on your application. You'll feel and hear the difference! Loud Mouth Systems are available with 3.5'' slash-cut or 2.5'' dual/dual hand-polished tips and include all necessary installation hardware.