So its made by 'Revolution', sounded good up until I put the test pipe on. I'm selling the complete testpipe-back and I'm unsure of the piping size because I bought my car with it, and it's never been removed. As soon as i get it off I'll get more info, my guess is either 2 1/4 or 2 1/2. With the test pipe it should fit perfectly on a ek (96-00) civic coupe, maybe eg (92-95) civic coupe as well. Does not fit well on my teggy with the test-pipe, and since one bolt didnt line up perfect i had an exhaust leak . I have a sound clip of it before the test-pipe, I'll try to post it. Oh and price is 175 obo. Anyways pic (sorry they're not great):