Abstract: An air-bag unit (1) adapted to be positioned on a floor pan of a motor vehicle in the foot-well to be located beneath the feet of an occupant of the vehicle has a substantially sealed damp-proof housing containing an air-bag (11) formed of fabric, the housing having a substantially rigid upper cover (8), the unit being such that on inflation of the air-bag (11) the cover of the housing is lifted, from its initial position to an elevated position.