Abstract: The present invention relates to apparatus for filling an empty, flexible container (8) with gas essentially instantaneously when subjected to powerful retardation forces, wherein the gas-filled container (8) functions as a force-absorbing cushion which protects against injuries, wherein the apparatus includes pressure receptacles (1, 2) which is filled with gas under high pressure, a conduit (5) which connects the receptacles (1, 2) with the container (8), means for opening the connection between the receptacles (1, 2) and the flexible container (8) when subjected to retardation forces that exceed a smallest value, a container-holding device (7), and a retardation meter. The vessel is comprised of two pressure receptacles (1, 2) which are each sealed by means of a closure means and each of which has a respective connection conduit (3 and 4) which joins pressure receptacles (1, 2) to the flexible container (8).