Abstract: A one-gauge one-turn regulator manifold includes a manifold body, a spring set, a knob set, an annular dial and one inlet pressure gauge. The outlet pressure is selected and adjusted by turning a control knob without a pressure gauge. The control knob with a marker indicating the outlet pressure from zero to maximum is rotatable within one turn. The knob set contains one adjusting screw which is used to fine-tune the pressure, and thus the outlet air pressure is calibrated as expected. The annular dial with pressure tick marks is located between the control knob and the manifold body. The outlet pressure is easy to selected and controlled by turning the knob to the desired pressure makers on the dial without the pressure gauge.