An airbag system includes an airbag and an inflator positioned in an instrument panel. The airbag includes a first chamber and a second chamber spaced from the instrument panel by the first chamber. A plurality of tethers is positioned within the second chamber. Each tether is coupled between a central area of a lower side and a central area of an upper side. A first and second lower extensions and a first and second upper extensions extend from the lower side and the upper side of the airbag, respectively.