SLP's Camaro/Firebird Loud Mouth has always been one of the best-performing cat-back exhaust systems in the business. Now it's available with SLP's Loud Mouth II Mufflers for a slightly lower tone. They offer flow and performance similar to their Loud Mouth resonators but have a ceramic-wrapped, perforated core that reduces high-frequency noise and in-car resonance for complete control over your car's sound and performance characteristics.