Gasket for header?

Well I got a kamekazi 4-1 header a couple months ago and just recently a shop told me that I have an exhaust leak where the header meets the collector. They told me I need to get a metal gasket in place of the crappy one that I recieved. My problem is, I bought the header off ebay and have no clue on how to get a gasket to fit. Any ideas? I know the collector is 2.5in

Where the header meets the collector on a DC header is two ring type gaskets. They are compatible with the OEM Honda ones.

Check it out.