gt35 turbo an4 oil feed restrictor fitting inlet t25 t28 gt25 gt28 t3 m12 x1.0 xs power copper turbo oil feed restrictor fitting for many turbos, gt35, t25, t28, t3, t4, t6 an4 fitting size to oil line m12 x1.0 thread to turbo oil fitting has built in restrictor to supply proper oil pressure for the turbo which is critical for normal turbo operation. without correct restrictor, turbo oil seal might be blown and leaking oil.