Blow off valve to suit MY02 onwards, Impreza WRX and STi. (GD and GG models) Kit includes all parts to bolt directly to OE intercooler as well as custom bolt up flange to fit return hose. Unique design allows both venting to atmosphere to give that unique "whoosh" noise as well as part venting back to inlet to stop over fueling and poor idle. ( We have not seen this problem with this BOV ) (normally associated with externally venting BOV's)adjustable spring tension. Available in Red,Blue and Silver.