Cashco's recently release of a new ULR-1 valve not only brings an enhanced product, but also clarification and new information. The ULR-1 is a DA4 with a Cashco CA1 back pressure valve mounted onto it. Using the inlet pressure from the valve, the CA1 is "set" to control the outlet pressure of the main valve. However, because the outlet of the CA1 constantly exhausts into the atmosphere, the media through the valve must be environmentally safe gas such as oxygen or nitrogen.