These oil pumps are a good upgrade for all EJ20 and EJ25 engine pre 2008 or non STi models.Higher flow than the 10mm
The stock 10mm pump on older EJ20 and WRX EJ25 is adequate in stock form, but once you start adding mods and pushing your vehicle, you can run into oiling issues.
2010-2013 Outback and Legacy Turbo 2008-2015 Impreza Sti Turbo are direct fit