This fit system will work with the 2006-present Decibel Aurora Instinct Air-8 & Deviant helmets.> Any helmet with the Brain Trust can not be retrofitted with this Pro Fit 2 system.> Unlike the Pro Fit 1 system the Pro Fit 2 system does have 2-position rear vertical adjustment. The Pro Fit 1 has no vertical adjustment.> The Pro Fit 1 System is not interchangeable with the Pro Fit 2 System & vice versa.