HKS had a lot of people over tightening the adjustment screw, and bunking up the valve. So they decided to do away with it and save money on repairs. If you can get one with the adjustment screw that still works OK, go for it. I'm not 100% sure if there is any difference in product name between the two... SSQV is the full acronym for it - SQV is just somebody leaving off the "Super"