The accelerometer includes an inertial mass, a fixed base and at least one or more supportssensors for supporting the mass from the base rendering the support system statically indeterminate. Accordingly, additional bits resulted from increase of a number of intra prediction mode are effectively reduced. Inner extremities of the flexible inner and outer panels of the air bag guide are respectively secured by a first connector that mounts the air bag module and a second connector to the frame, and the trim cover is secured to the frame by a third connector.