A device for regulating the pressure and/or flow of pressurized gas, comprising a body with a gas inlet, a gas outlet and a gas passage connecting the outlet with the inlet, a pressure reducer and a flow selector arranged downstream of the pressure reducer, a hand-wheel rotatably mounted on the body and cooperating with the flow selector for adjusting the flow, and a pressure indicator located at the center of the hand-wheel. The device comprises also a shaft rigidly fixed to the body and rotatably bearing the hand-wheel, the shaft supporting the pressure reducer and comprising a gas channel fluidly connected to the gas passage in the body.