GT SPEC stainless Steel Uppipe. Including EGT bung for stock sensor. This uppipe has one of the biggest diameter in the market. Provide excellent mid range to hign end horse power. A must for an upgraded turbo. Uppipe to Turbo diameter : 2"" uppipe to manifold diameter: 2.3"" Car Manufacturer: SUBARU Application: GDA04 (04 WRX),GDA02 (02 to 03 Impreza Sedan),GDBC (04 STI),GGA (02+ Wagon)