Model HP 722 is an electroless nickel-plated brass barstock two-stage cylinder regulator with a stainless steel diaphragm for constant delivery pressure from full to near empty cylinder conditions. Model HP 722 is suitable for Ultra-High purity gas applications, research sample systems gases, process analyzer gases, gas chromatography, EPA protocol gases, laser gas systems and emission monitoring systems. Recommended for gas purity levels of Grade 5.0 (99.999) and higher. Front and back panel mountable.