Highly recommended!
Working pressure of the valve. Note that the cylinder needs to have the same working pressure!
Standard O-rings are suitable when using air. Viton O-rings are used when diving with Nitrox- Enriched air. However, they can also be used with air. Viton O-rings are generally recommended.
This is the screw thread of the valve where the 1st stage is connected. G5/8 is the standard screw thread. M26 is the screw thread which is wider, and is specifically used for Nitrox regsets with the same screw thread- NOTE: M26 is the EU standard for NX
