Review on Silent Performance: Unleash the Power with MBRP M1004A Universal Quiet Tone Muffler by Scott Kalinowski

Good design and perfect fit. I installed it on my Duramax 2010. I definitely helped muffle the 4 inch exhaust. It still has a nice smooth sound coming from the outside of the truck. But not evil, like a straight pipe. No complaints! I hooked it up to a 17" RTD resonator and it was as quiet as a factory in the cab. what I intended.