I saw these on eBay and had to try them. They are 1.75" inlet diameter and bolt right on the factory header where the factory mufflers come off. They look nice but not deep enough sounding with baffles in them. This is due to their canister size. Here is a video with the factory baffles in and I will take another video with them out later once she has cooled down. They are very Kool for custom applications.