barely used, HKS Super Sequential Blowoff Valves (SSQV) are dual stage pull type relief valves that by design do not leak under high boost conditions or under idle vacuum and is actuated by pressure alterations to ensure a quick primary and secondary valve response. Part # 71004-AF008 SSQV Kit : SUBARU Impreza WRX STi 2005-2006. originally $320.00