The Milwaukee MA957 High Quality CO2 Adjustable Flow Pressure Regulator has a Solenoid, a 4' cord, standard brass fittings, diaphragm valves and a bubble counter. Designed to be used with ALL Milwaukee MCXXX Controllers such as MC122 and MC125.The Milwaukee MA957 CO2 Adjustable Flow Pressure Regulator is a High Quality brass fittings regulator, designed for long lasting use in your Aquarium and Hydroponics applications. Can be used with all Milwaukee controllers. Set of one (1) per package.