This is a brand new 6-Speed Transmission that came in the 2007 STI.
2007 STI Transmission with 2002 - 2003 WRX Install Kit:
2007 STI Transmission with 2004 - 2005 WRX Install kit:
As the 2002 - 2003 install kit, but with parts that allow you to use your 04 -05 front WRX Axles.
With Either Kit, the only additional parts that you would need are a cluch and flywheel if you chose to put a new one in, the shift-knob of your choice, a drive-shaft, and a DCCD controller if you chose.