I was looking for a SILENT 3" muffler. There aren't very many lots of them.Most mufflers are designed to make cars louder but can still pass the test.(which I understand) I like this muffler because I'm doing a sleeper on my Saab and I need something super quiet and discreet what didn't make my 4 cylinder "rice" ring either. It went with it perfectly. I couldn't find any good reviews for this muffler, but it was one of the largest (and cheapest) mufflers on the market. In addition, the design features Baffles and fiberglass In hindsight I probably could have gotten by with just a baffle design (because I put that on e of a really good resonator) and benefited from less back pressure. never mind although. Very soft, deep exhaust sound. maybe the low tone is also due to the turbo, catalytic converter and good resonator. Yes, it's made of aluminized steel. 3 inches in and out offset (center, side) omnidirectional. You need to weld the exhaust hangers to it and then attach the exhaust pipe.