Propane Refill Adapter with Pressure Gauge and On Off Control Valve Gas Elbow Adapter for 1LB Tank 120LBS QCC1 Cylinder 1On Off Control Valve: The elbow gas adapter is equipped with on off control valve, prevents gas leakage when connecting cylinder, and easily controls the filling process. 2Easy Connection: The propane filling adapter has handwheel handle for tightening, making it easy to connect large steel cylinder to a 1LB propane tank. 3Quick Monitoring: Quickly check the remaining gas in your large gas tank to avoid inconvenience caused by insufficient gas during the refueling process. 4Brass Material: This gas adapter adopts solid brass material, providing good sealing effect and corrosion resistance, and can be used in various environments. 5Convenient Use: The 1lb bottle can be easily filled multiple times without tools, and the built in safe function effectively prevent the danger of overinflating the cylinder.