I thought that too, I never had or need that adapter thingy
Sorry guys but you have to use the adapter funnel impossible to fit without it as the MAF bolts directly to the back of it, the filter then fits to the ring and is secured by the large jubilee clip.
http://jimwolftechnology.com/wolfpdf/PO ... NSTALL.PDF
I think they ship with the adaptor already fitted atleast mine did