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 decompression device to reduce pressure. < p>Double pipe, provide welders, reduce costs. Features: Mainly used for welding, welding process, etc. Product Description Material: Metal Color: Gold Content: 1 x Mig Tig CO2 Flow Meter Only the above package content, the products are not included. Note: Light irradiation and different displays may cause the color of the item to be slightly different from the real thing. The measurement allowed error is +/- 1-3cm.