Gas bag

The utility model relates to an air-bag particularly to a single air-bag which comprises double sheet layers. The bottom of the air-bag is connected with a fixing board and then forms a single-layer air-bag, after being fixed, the inflation and the contraction of the single-layer can massage the body and can achieve the purpose of comforting the body, recovering from the fatigue, saving working time greatly and increasing the competition. The fixing board is of plate shape and of plastic, a hole is arranged in the center of the fixing board, two holes for fixing buttons are arranged on the two ends of the fixing board, a plurality of fixing holes for spare parts are arranged on the other end, two thin loaf-shaped openings are arranged on the corresponding inner side of the two bottoms, equidistant spacing cutting along the edge of the fixing board forms the equidistant spacing board which has spring distorting capability after being imposed by power to support and protect the deck body to form the steady state.