Oxygen pressure regulator
Oxygen pressure reducers are generally pressure reducing devices for bottled gases. Ensure that the outlet pressure remains stable when there are changes in the inlet pressure and outlet flow rate. An increase in the reading of the low pressure gauge may indicate potential dangers and hazards.

Oxygen pressure gauge (oxygen gauge) refers to a pressure gauge used to measure oxygen pressure. The pressure gauge measures the gauge pressure due to the strong oxidizing nature of oxygen, which requires a special pressure gauge when measuring oxygen pressure. This type of pressure gauge is called an oxygen pressure gauge.
So they are different!