Genuine HKS SSQV 4 Blow off Valve kit 

WRX     VAG    FA20(TURBO)    14/08-    71008-AF015

Installing this product creates unique sharp & high frequency SQV sound. The SQV IV unit is designed to be located beside the engine so the appurtenance of the engine bay is improved.
The suction-return parts are included (those are necessary to pass the Japanese Automobile Inspection.).
Any engine failure such as engine stall was not occurred during the in-house testing.

SSQV4 is the lastest Blow Off Valve from HKS Japan and comes with everything you need to install it . 

English instructions included 

HKS-71008-AF015

HKS Super SQV (Super Sequential Blow Off Valve) uses a unique sequential valve structure and a differential pressure control system, which allows for a broad operation range from low boost to high boost. All vehicle specific Super SQV kits include both the HKS Triple Fin Sound insert and Recirculation insert