This hose kit contains an odd set of hoses. After looking at numerous photos online it appears that the kit was designed for right hand drive cars, so the large 'mysterious' hose that several other reviewers have mentioned is actually the heater core inlet hose for a right hand drive STI.On is a left hand drive STI steering wheel (or Forester XT, '07 in my case) this hose can probably be used for either of the heater core hoses or the large power steering hose. The hoses are good quality and a bit too long (which was good as I installed them on a Forester and needed a bit of play as my engine bay is a bit different). I've attached a picture of where all the hoses from the kit go. If you need those hoses this is a great kit. If you're expecting PCV hoses, this is a worthless kit. If you have an IAG AOS (second picture) you don't need a turbo boost hose. Unless you need power steering or a heater core hose, this is another hose that's useless.