SR20DET GT28R GT28 T28 T25 Turbo Adapter Flange CNC Billet Aluminum Flanges/Adapter for GT25R, GT28, GT28R turbo Like the ones on SR20DET Engine Inlet Adapter is 2 Bolt, 2.25" O.D Outlet Adapter is 3 Bolt, 2" O.D Bolt On to Compressor housing inlet and outlet.