You want a ~3.5" or 90mm O.D. MAF adapter.
Most of the adapters that have been popping up are way too small! (like 65-80mm OD)
Do not waste your money of a small unit!
Also DO NOT get the adapter screen unless you have the stock MAF. Even then it has been proven it is really not needed with a little MAF re-orientation.
Also depending on the adapter you get you will not want to run the Smaller screen anyway!