Abstract: An electric squib igniter and a gas generant composition surrounding it are enclosed in a hermetically sealed container. This is enclosed in an inner housing which is surrounded by an annular outer housing. An annular filter surrounds the gas generant composition inside the container, which is rupturable through orifices in the inner housing by gases produced when the gas generant composition is ignited. A cooling device in the annular chamber between the two housings is positioned between the orifices of the inner housing and peripheral orifices in the outer housing, through which the filtered, cooled gases may be expelled radially into an inflatable structure. A mounting flange fixed to the outer housing is provided for attachment to related apparatus.