Its Pull-Type relief design ensures stable operation regardless of the amount of boost pressure. 100% Genuine HKS Super SQV IV Universal Blow Off Valve. 【SUPER SQV】.
I bought a genuine SSQV 4 since the knock-off version wasn't venting well at low rpm and light boost, however, the genuine one has the same issue. The spring itself is a little hard and so only opens at idle and wide open throttle. If there was a way to adjust the spring enough to compensate (like the first gen version), it'd be great!
The sound however is awesome!