ISTA CO2 SetTUV safety regulation approved seamless aluminum CO2 cylinder. Supporting base included to prevent chance of falling of the CO2 cylinder to lead to further damage to the CO2 regulator. Pressure reduced design to provide most stable and reliable pressure output 3 in 1 compact CO2 diffuser with CO2 bubble counter, check valve and diffuser easy in installation, assurance of best diffusing effect and easy ceramic replacement. Pipe holder to prevent CO2