Hybrid Dual Port Blow Off Valve For Subaru Impreza WRX 04-18 and 05-09 Legacy GTHybrid Dual Port Blow Off Valve For Subaru Impreza WRX 04 18 and 05 09 Legacy GT Up for sale is an adjustable Dual Port Blow Off Valve, brand new in box available in Blue and Black exactly as shown on the picture. These units are fully customize able and are 3 in 1 in terms of functionality. They could be run as: Fully venting off to atmosphere (a. k. a SuperSonic) Fully recirculating like a diverter valve, except still make the sweet BOV sound (a. k.