The pressure decompression valves can mutual-fill several gastank that are not fully used with each other. When the gastank can not be filled continuously due to the high pressure of the gastank during the filling process, the excess pressure can be decompression from the gastank by pressing the pressure decompression button to continue filling. With the extension pole, it can be used to connect the gaslamp, and the flamepower of the gaslamp can be controlled through the valves.    Features:  Multiple unused gastanks can be collected to one gastank through the pressure decompression valves for reuse to avoids waste. During the gasfill process, when the pressure is too high to fill, you can press the pressure decompression button to continue.  The extension pole is made of fine quality aluminum alloy material, long service time, accurate machining, quick connection of threaded joints, built-in locking device to prevents thegas from spraying.  The extension pole can adjust the lamp height.  Easy to store and carry.  It is more convenient to use lamp outdoors.    Specifications:  Type: Set A, Set B (optional)  Material: aluminum alloy+brass  Pressure decompression valves size: 140 * 95 * 16mm  Extension pole size: 118 * 16 * 16mm  Pressure decompression valves weight: 36g  Extension pole size: 47g  Package size:  Set A: 120 * 50 * 50mm / 4.7 * 2.0 * 2.0in  Set B: 120 * 20 * 20mm / 4.7 * 0.8 * 0.8in  Package weight:  Set A: 88g / 3.1ounce  Set B: 50g / 1.8ounce    Packing List:  Set A:  1 * Pressure Decompression Valves  1 * Extension Pole    Set B:  1 * Extension Pole