Traditional screw valve is sandwiching between top and bottom fabric. However, it is only good for mat that is not very thick. Air mat is too thick for this kind of valve and cause a lot of air leakage around the valve socket. The bulge type valve is good but not good enough.
ALL-in-One valve is concealed into the mat. It can in-flow and out-flow.
By un-plugging the BLUE cord, air can be blown or pumped into the mat.
By un-plugging the RED cord, air will be purged out.
By pressing the GREEN button inside the valve body, excess air can be purged out in order to adjust the hardness.