The all new HKS redesigned Super Sequential Blow-Off Valve 4 (SSQV4) for the 08-14 WRX features the same high performance dual stage pull-type valve design with an all new redesigned exterior styling. Since 1994, the SSQV has a proven itself to be one of the most versatile blow off valve systems on virtually any turbocharged performance level, from showroom stock to fully track prepped. Unlike typical push type blow-off valves, the pull-type design of the SSQV4 makes this valve virtually impossible to leak under load, as it uses the boost pressure itself to seal the valve closed when on throttle. While imitators have also adapted this concept, they typically utilize only a single large pull-type valve. These imitation valves react slowly, require high pressure to open and are not able to activate at light-load conditions. Traditional smaller push-type valves can react faster but lack the ability vents large boost pressures. The HKS SSQV4 has solved both of these problems by incorporating two sequential valves in one, a small primary valve for ultra quick activation and a larger secondary valve for additional discharge capacity. The SSQV4 is engineered to only open the small primary valve under light throttle conditions, and open the secondary valve for additional relief capacity under high boost and load conditions. Constructed from brushed aluminum, the SSQV4 utilizes a unique circular mounting flange and integrates with an industrial C-clip snap ring and O-ring gasket assembly to ensure a perfect seal. The included triple-fin discharge port produces a powerful, unique and aggressive blow-off sound. If desired, the triple fin insert can be removed or swap with other inserts (not included) to produce a more customized sound. The HKS SSQV4 is designed as a 100% venting blow off valve, but can be modified to function as a recirculating valve with additional parts (not included).