ISTA Co2 Pressure Regulator Magnetic Valve Bubble Counter - Adjustable Solenoid 1. CO2 Pressure Regulator (Magnetic Valve included) has passed quality testing. It is ready to install without any further adjustment. 2. Easy to install and maintain. ISTA CO2 Pressure Regulator (Magnet Valve included) is a high quality product. It can be ready to install without any further setting or adjustment. For the sake of safety, the following. fits Australian, Asian, European standard type refillable co2 cylinder. or, "no pin" US refillable co2 cylinder.