One gauge shows pressure for carbonating and dispensing. The other gauge displays how much Oxygen is left. Easy to use dial for pressure adjustment from min to max. Pressure safety relief valve which can be pulled to release pressure when disconnecting. brass body, accurate machining, chrome plated , more durable. Economy style flow meter regulator. Single stage piston design. Machined brass body. Combination of regulator and flow meter as one unit. Polycarbonate flow tube and outer cover are impact resistant for maximum durability. Compact construction. Designed for MIG & TIG applications and provide accurate regulator of gas flow. Dual scale gauge with unbreakable polycarbonate lens for durability. Measuring range: 0-2.5(MPa) Material: copper Color: as shown Package Contents: 1 x oxygen meter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.