To complete my MCCR DS 2009 and to extend the maximum depth limits, it was necessary the RG-UF/M regulator replace through a first stage with higher constant middle pressure. Therefore it is necessary have one push-valve with orifice ( KISS valve, Hydrogom, O2 Booster, etc.) to buy normally for about 200-300 €. I built my own, the material costs about 10 euros. It has a built-in needle valve for adjustment of the constant mass flow CMF..