Vayu means air. This simple mudra can balance the gas imbalance in stomach and body. The problems causing with gas can be eradicated.
There is no need to tell more about the mudra pose, you can simply understand from the photo itself. Use both hands to do the mudra. There is no time restriction, you can do it by sitting, standing or by laying down.
Keep the concentration on breath and the pressure between the thumb and index finger's joint. Do it 10 to 20 mins as per your convenience.
It will clear air blocking problems in stomach, clear chest problems due to gas, and reducing rheumatic.