The Mancraft group have released another HPA airsoft product --- the Mancraft Air Stock Support (M.A.S.S.)... "So there it is: M.A.S.S. MK1 - Mancraft Air Stock Support MK1. It can accommodate 13ci (0,21l) HP tank and regulator (Mancraft regulators fits, Wolverine reg will fit as well, Redline, nijna - the same thing - they all should fit and not be visible too much. At the back you have hole to put small manometer.