4.2 The rotating head turned to the right. To rotate the arrow that says open to test whether there is or not n2 if n2 is the original, close the valve head .
4.2, rotate head to speak towards the right will rotate according to the arrow that says Open to test whether N2? N2 is removed, close the original sparkle head .
4.2 to turn the flame to the right to turn the arrow wrote: Open N 2 to test whether there is or is not N 2. If there is, and then turn off the flame intact