This is a Magnaflow XL, which means it is a 3-barrel turbocharged muffler and not the typical Magnaflow straight-through muffler. It's a little quieter, but with the same deep tone without creaking or popping. This is probably one of the quietest mufflers on the market. As for the comments that this is fake, this is just someone's unfounded opinion. Yes, it is slightly different from other Magnaflow mufflers as it is a different type of muffler. They are not embossed with the MF logo. I've ordered this part number from Revain twice and each time it came in a Magnaflow box with the same stickers and paperwork that you get with every Magnaflow. And for the digital calipers, the size of the muffler depends on the inner diameter of the inlet/outlet, just like any other muffler.