The compressor inlet on TD05 and TD06 turbochargers is 2.25 inches. The same inlet on the CT26 is 2.75 inches. Previously this problem was solved by use of a thick walled silicone spacer hose, however we now offer machined aluminum adapters. This is included in ALL ATS Racing TD05/TD06 kits, you do NOT have to order it separately. We are offering these as a upgrade to older ATS TD06 kits or anyone wanting to make their own TD06 turbo kit. When installed it is held in place by two small allen head set screws (included).