The Oxygen regulator is made by Sherman, the brand speaks for itself, it's quality and reliability is well known among welding specialists.
The regulator allows to decrease a pressure of a gas coming from a bottle to desired level. The outer pressure level can be maintained regardless of spikes and falls of input gas pressure. The regulator is equipped with a safety valve, if the pressure excess safe level, it is released outside.
More technical information can be found on the right hand side
Sherman Oxygen gas twin gauge regulator
Input pressure [bar] 200 Output pressure range [bar] 0.5 - 10 Maximum flow rate [m 3 / h] 30 Thread inlet (EU Standard) W 21.8 x 1 / 14 Thread gauge G 1/4 Outer thread (ø) [mm] 6.3