Gas tank filling: Inflating is generally done from top to bottom, from high pressure to low pressure. It is recommended to cool the inflated tank in the refrigerator for 30 minutes before inflating. Warning: Operation must only be performed by professionals and in accordance with relevant national safety standards. It is strictly forbidden to inflate MAPP gas or liquefied petroleum gas into flat gas tanks or cassette gas tanks. Inflation must be carried out outdoors. During the inflation process, non-gaseous contents in the tank may accumulate at the upper part of the gas tank and can be discharged through the pressure release button (press for about 2 seconds before inflating). Note: When releasing pressure, the air valve must be closed, and the device must be installed in the correct direction. The gas in multiple unused flat gas tanks can be collected into one gas tank through this valve to enable reuse. This valve is compatible with cassette converters and other standard converters to allow gas transfer between tanks, regardless of orientation, and can be connected flexibly. The switch core is made of 58 copper for durability. The gas seal uses fluoroplastic O-rings, resistant to wear, chemicals, low and high temperatures, and functions normally within -20°C to 250°C. Double O-ring design ensures sealing: one for airtightness and one to prevent leakage. Gas cylinders may vary in type, but different gases must not be mixed. Always use the same type of gas. A bottle collecting residual gas cannot be filled to 100%, and a new gas bottle should not be completely full either. Two effective methods: Method 1: A simple and practical method – place both the source tank and the receiving tank in the refrigerator for 20 minutes without releasing pressure, then connect immediately after removal. The cooled tank has lower pressure, while the one at normal temperature has higher pressure, allowing high-pressure gas to naturally flow into the low-pressure tank. Method 2: When no refrigerator is available outdoors, connect the gas tanks, turn off the switch, and release pressure five to six times. After releasing, open the valve to resume operation. Pressure release alone does not ensure complete transfer. If pressure release fails, combine it with shaking the upper tank and warming it by hand. Hold the upper gas tank (bottom of the outlet pipe) and shake it back and forth while warming it with your hands to increase internal pressure. The combination of increased pressure and periodic release allows gas to flow naturally to the lower-pressure tank. Slightly exposing the upper residual gas bottle to sunlight may also help increase pressure, but avoid prolonged exposure. Color: Grey & Red Material: Aluminum Alloy + Copper Package Contents: 1 * Camping Gas Saver Note: Light reflection and display differences may cause slight color variations between the image and the actual item. Measurement allows an error of +/- 1-3 cm.