A nasal cushion comprises a substantially triangularly shaped frame from which extends a membrane. The pressure reducing portion limits the thickness of the airbag in the widthwise direction of a vehicle and prevents the arm from being pressed inward in the widthwise direction. The reception device, while receiving the content data transmitted by the transmission device, stores received data into a storage device and also reproduces content based on the stored data. The electronic device samples, recombines and decodes the left channel audio signal and the right channel audio signal according to a decoding matrix, which is the inverse of the mixed matrix, to revert to the original multi-channel audio file. In addition, the opener has a spring with one end fastened to the base metal plate while the other end is fastened to a spring lock pin of the opener beam.