Abstract: A flexible hollow body fillable with fluid medium and formed of a double fabric having an upper web and a lower web respectively having an outer surface with a layer of elastomeric material and forming an inflatable chamber therebetween including a coated cover fabric applied to at least one of the layers of elastomeric material, the cover fabric having strip-shaped regions detached from the layer of elastomeric material to which the cover fabric is applied so as to define respective tubular chambers; angular strips disposed within the tubular chambers at respective edges thereof for joining the one layer of elastomeric material and the coated cover fabric to one another; the tubular chambers being formed, respectively, with at least one inlet opening for inflating the tubular chambers.