" When the inlet pressure and outlet flow change to maintain a stable outlet pressure. Hyperbaric oxygen in the cylinder, acetylene gas dissolved after decompression, uses a pressure reducing device. < p>Double pipe, provide welders, reduce costs. Features: Mainly used for welding, bonding, etc. > Product Description Material: Metal Color: Gold Contents of: 1 x CO2 Mig Tig Flow Meter Only the above package content, no package content, other products are not included. Note: Light irradiation and different displays may cause the color of the item to be slightly different from the actual color. The measurement allowed error is +/- 1-3cm. "